Civil Service - Electrical Engineering Prelims 1998-2007

1 of 14

1. The open-loop transfer function of the

control system shown in the figure is

a.

10

1 2s s s

b. 0.6

c.

6

1 2s s s

d. 3 2

10

3 2 6s s s

2. If the single flow graph shown in the given figure has M number of forward paths and P number of individual loops, then

a. M = 6, P = 6 b. M = 6, P = 4 c. M = 4,P = 6 d. M = 4, P = 4

3. The impulse response of a system is given

by c(t) /21

2te Which one of the

following is it’s unit step response? a. 1/21 te b. 1 te c. 2 te d. 21 te

4. If the open-loop transfer function of a feedback system is given by

22 2 5

KG s H s

s s s s

the

centroid of the as motes will be a. -1,0 b. 1.0 c. 0,-1 d. 0,1

5. The first element of each of the rows of a Routh-Hurwitz stability test showed the sign as follows:

Rows I II III IV V VI VIIISings + – + + + - + The number of roots of the system lying in

the right half of s plane is a. 2 b. 3 c. 4 d. 5

6. The performance specifications for unity feed control system having an open-loop transfer function

1 2

KG s

s s s are

1. Velocity error coefficient 110secVK

2. Stable closed-loop operation The value of K, satisfying the above specification is a. K>6 b. 6<K<10 c. K>10 d. None of the above

7. The effect of phase-lead compensator on gain cross-over frequency egW and the

bandwidth bW is that

a. Both increase b. Both decrease c. egW increase while bW decrease

d. egW decreases while bW increases

8. A liner 2nd order single input continuous time system is described by the following ser of differential equations:

1 1 22 4X x x

2 1 22X X X u t

Where 1X and 2X are state variables and

u(t) i9s the input. The system is a. Controllable and stable b. Controllable but unstable c. Uncontrollable and unstable d. Uncontrollable but stable

9. For

C.S.E Pre-1998

EELLEECCTTRRIICCAALL EENNGGIINNEEEERRIINNGG

2 of 14

2 2

2 2

6 1

6 5 6 55

6 5 6 5

s

s s s sss

s s s s

The coefficient matrix A is

a. 6 5

6 0

b. 5 5

0 6

c. 6 0

5 6

d. 0 1

5 6

10. Which of the following quantities are-analogous in a force-current analogy? 1. Displacement and inductance 2. Velocity and voltage 3. Mass and capacitance Select the correct answer using the codes given below: a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

11. If R and X are the resistance and indicative respectively D and L are the diameter and length respectively of the rotor of a two-phase ac servomotor, then the ratio D/L and X/R will be respectively a. Large and large b. Large and small c. Small and large d. Small and small

12. In the case of an armature controlled de motor, if the equivalent moment of inertia of the motor and load is made small and the armature resistance is reduced, then the motor tends to act like armature resistance is reduced, then the motor tends to act like a. A differentiating circuit b. An integrating circuit c. A PID controller d. A second order critically damped

system 13. To detect the error between a reference

shaft position and an output shaft position which of the following error detectors can be used? 1. A pair of tachogenerators 2. A pair of potentiometer 3. A synchrony pair

Select the correct answer using the codes given below: a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

14. When 30V dc is applied to the vertical deflecting plates of a cathode ray tube, the bright spot moves 1cm away from the centre. If 30V (rms) ac is applied, then the movement of the spot will be nearly a. 1 cm b. 1.5 cm c. 2 cm d. 3 cm

15. A spectrum analyzer can be described as a. Voltage selective frequency meter b. Correct selective frequency meter c. Frequency selective voltmeter d. A filter

16. Let dM

d be the rate of change of mutual

inductance between the fixed and moving coils with respect to the angular deflection in an electrodynamics spring controlled ammeter. Which one of the following is the correct condition for obtaining a liner scale in the ammeter?

a. dM

d

is constant

b. 1 dM

d is constant

c. 2 dM

d

is constant

d. 2

1 dM

d is constant

17. A current

1 2 sin 314 30 2sin 1570 20t t amperes is measure with a thermocouple typw ammeter. The meter will read a. 2A b. 2A

c. 3 2 A

d. 4A 18. A thermocouple produces a voltage of

50mV. Its internal resistance is 10 . The output is read by a PMMC meter having an internal resistance of 120 . Output voltage indicated will be a. 50mV b. 40mV

3 of 14c. 33.3mV d. 25.0mV

19. The three impedances of an ac bride shown below re

1 200 60Z

2 400 90Z

3 300 0Z

The value of Z4 for the balanced bridge is

a. 150150

b. 150 30

c. 600 30

d. 600 150 20. Match List I (Type of instrument) with

List II (Suitability for measurement) and select the correct answer using the codes given below the lists: List I A. Moving iron B. Electrodynamics C. Induction D. Electrostatic List II 1. ac/dc voltage only 2. ac/dc voltage/current/power only 3. ac voltage/current/power 4. ac/dc voltage/current/power 5. de voltage/correct

A B C D a. 2 4 3 1 b. 2 4 1 3 c. 1 2 3 5 d. 1 2 5 3

21. In a Wheatstone bride3, the known resistances are correct to within 0.1%. the accuracy to which an unknown resistance can be measured is a. 0.4% b. 0.3% c. 0.2% d. 0.1%

22. Match List I (unit) with List II (Equivalent unit) and select the correct answer using the codes given below the lists: List I A. Weber

B. Coulomb C. Farad List II 1. Ampere-second per volt 2. Volt-second 3. Ampere-second 4. Volt per second

A B C a. 1 2 3 b. 2 3 1 c. 2 3 4 d. 3 1 4

23. A special purpose diode which uses metals like gold, silver or platinum on one side of the junction, n-type doped selicon on another side and has almost no charge storage in the junction, is a a. Schottky diode b. Tunnel diode c. Varactor diode3 d. Zener diode

24. Consider the following statements 1. BJT needs bias stabilization because its

COI increase with increase in BEV and

temperature. 2. Thermal runaway may be avoided by

choosing 1/ 2CE CCV V

3. FET and BJT both need bias stabilization because both ate semiconductor devices.

4. By increasing ER bias stabilization

improves. Of these statements a. 1 and 2 are correct b. 3 and 4 are correct c. 2 and 3 are correct d. 2 and 4 correct

25. The overall voltage gain in a small single transistor CE amplifier is given by

a. 1feV

ie s

h RA

h R

b. 1feV

ie s

h RA

h R

c. /

fe tV

ie s L

h RA

h R R

d. /

fe LV

ie L s

h RA

h R R

26. A feedback amplifier has a closed-loop gain of -200. it should not vary more than 50%, despite 25% variation in amplifier gain A without feedback. The value of A is

4 of 14a. 800 b. -800 c. 1000 d. -1000

27. Match List I (Device) with List II (Property) and select the correct answer using the codes given below the lists: List I A. Planar monolithi9c BJT B. Thick film C. Thiin film D. Opt coupler List II 1. Low-cost resistors 2. Resistors suitable for high frequency

use 3. Isolator 4. High frequency transistors

A B C D a. 2 3 1 4 b. 4 1 2 3 c. 4 1 3 2 d. 2 3 4 1

28. Assuming that only the X and Y logic inputs are available and their complements

X and Y are not available, what is the minimum number of two-input NAND gates require to implement X Y ?

29. In 8085 microprocessor , H,L register pair is used for storing a. Address of memory b. Data c. Address of next instruction d. Current instruction

30. The RMS thermal noise voltages of three resistors individually are E1, E2 and E3. If these resistors are connected in series, the total noise voltage is given by a. 1 2 3E E E

b. 2

1 2 3E E E

c. 2 2 21 2 3E E E

d. 1/3

1 2 3E E E

31. For three links in tandem, each of the first tow has S/N ratio of 60dB while the third has the same 40dB.The overall S/N ratio (approx) is a. 30dB b. 40dB c. 50dB d. 60dB

32. A 10MHz carrier of peak value 10V is amplitude modulated by a 10kHz single of amplitude 6V. The amplitude of each side band frequency is a. 3V b. 4V c. 5V d. 6V

33. Consider the following statements: Delta Modulation has some significant advantages over PCM as 1. It provides greater channel capacity for

a given bit-rate 2. It does not inherently require

synchronization. 3. It is more tolerant to system noises Of these statements a. 1,2 and 3 are correct b. 1 and 2 are correct c. 2 and 3 are correct d. 1 and 3 are correct

34. Consider the following statements: Equipment is available to enable carrying more than one voice channel on 1. A pair of wires 2. A coaxial cable 3. A radio link 4. An optic fiber Of these statements: a. 1,2 and 3 are correct b. 2,3 and 4 are correct c. 1 and 4 are correct d. 1,2,3 and 4 are correct

35. consider the following statements regarding noise in pulse communication systems: 1. Those forms of pulse modulation

which transmit constant amplitude singles can be made to have good single-to-noise ratio.

2. For PWM and PPM, improved single-to-noise requires higher bandwidth.

3. In PCM, quantizing noise goes up if the number of standard levels is increased.

Of these statements a. 1 and 2 are correct b. 1 and 3 are correct c. 2 and 3 are correct d. 1,2 and 3 are correct

36. Control of dats flow within networks to ensure maximum efficiency and minimum interference between users, is achieved a. Through the isolation of usere

5 of 14b. Through magic-T networks c. By address coding d. By using system protocol

37. consider the following statements: The advantages of KU band for satellite communication are that 1. Heavy rainfall does not attenuate the

single 2. Frequencies are not shared with

terrestrial microwave radio system. 3. It has wide footprint 4. It has smaller antennas. Of these statements a. 3 and 4 are correct b. 1 and 4 are correct c. 2 and 4 are correct d. 1,3 and 4 are correct

38. Match List I (Data comm.. schemes) with List II (Applications) and select the correct answer using the codes given below the lists: List I A. Parallel synchronous B. Parallel asynchronous C. Serial synchronous D. Serial asynchronous List II 1. Commuter to computer 2. Computer to printer 3. Buses within computer 4. Telephone central office

intercommunication 5. Short distance data communication

A B C D a. 1 2 3 5 b. 5 3 2 4 c. 5 3 4 2 d. 1 2 5 3

39. The autocorrelation function of a rectangular pulse of duration T is a. Another rectangular pulse of duration

T b. Another rectangular pulse of duration

2T c. A triangular pulse of duration T d. A triangular pulse of duration 2T

40. The ISDN basic rate interface specified as per CCITT standards is a. One B channel (64kbps) and one D

channel (16kbps) b. Two B channels (64kbps) c. Two B channels (64kbps) and one D

channel (16 kbps)

d. Two B channels (64kbps) and one D channel (64kbps)

41. Which of the following circuits need to be checked to rectify a colour TV receiver showing no colour, monochrome picture and normal sound? 1. Colour killer 2. 3.58 sub-carrier oscillator 3. Chrome amplifier 4. Brightness control Select the correct answer using the codes given below:

Codes: a. 1 and 2 b. 1,2 and 3 c. 1,3 and 4 d. 2,3 and 4

42. A disadvantage of CW Doppler radar is that a. It does not given the target position b. It does not give the target velocity c. It requires a taransponder at the target d. It des not give the target range

43. In a decca chain of Decca navigation system, for a sub harmonic frequency ‘f’ what is the frequency of rhe master station? a. 8f b. 5f c. 6f d. 7f

44. In microwave communication, the antennas of one repeater must be accurately aligned with the next repeater in the link, because a. There are at least four carries with 600-

2700 channels per carrier b. A repeater must amplify the single

received c. The antenna beam widths are less than

20 d. The antennas are small in size

45. A dc shunt generator is running at rated speed developing its rated voltage. Match List I (Condition of operation) with List II (Effect) and select the correct answer using the codes given below the lists; List I A. The direction of rotation, residual

magnetism and field connections are reversed

B. The direction of residual magnetism and field connections are reversed

6 of 14C. The direction of ration and connection

of the field winding are reversed D. The direction of rotation and residua;

magnetism are reversed List II 1. The generator will build up with same

polarity 2. The generator will build up with

reversed polarity 3. The generator will not build up

A B C D a. 1 2 3 5 b. 5 3 2 4 c. 5 3 4 2 d. 1 2 5 3

46. In a dc machine, the armature mmf is a. Rectangular and directed along the

inter-polar axis b. Triangular and directed along the inter-

polar axis c. Triangular and directed along the brush

axis d. Rectangular and directed along the

brush axis 47. A shunt motor is running at its rated speed

on rated load. If the field circuit fets suddenly opened. a. Torque developed by the motor will be

almost zero and the motor will stop without causing any damage to the motor

b. The motor will draw very high armature correct but it will continue to drive the load at a reduced speed.

c. The motor would tend to race to a high speed while driving the load

d. The motor would draw very high armature current and will stall with consequent damage to the armature

48. The torque vs armature correct characteristics (A,B,C and D) of different types of dc motor are shown in the given diagram.

Match the curves A,B,C and D with the dc

motors given in List I and select the codes given below the list:

List I 1. Shunt 2. Cumulative compound 3. Series 4. Differential compound

A B C D a. 4 2 1 3 b. 4 1 2 3 c. 3 1 2 4 d. 3 2 1 4

49. When starting a differentially connected compound motor it is describable to short-circuit the series field winding to a. Avoid very high starting time b. Avoid excessive starting speed c. Prevent the motor form starting in the

reverse direction d. Avoid heavy in-rush of current

50. For a uniformly distributed winding of an alternator with a phase spread of degrees, the distribution factor is

a. sin

b. 2sin / 2

c. sin / 2

d. sin / 2

2

51. A single-phase alternator has a synchronous reactance of 2 ohms and negligible resistance. If supplies 10A to a purely capacitive load at 200V, then the generated emf will be a. 240 volts b. 220 volts c. 200 volts d. 180 volts

52. Suppose a synchronous generator connected to an infinite bus is supplying electrical power at unity PF to the bus. If its field correct is now increased. a. Both the active and reactive power

output of the generator will remain unchanged

b. The active power supplied will remain unchanged but the machine will also supply lagging reactive power

c. The active power supplied will increase and he machine will draw leading reactive power

7 of 14d. The active power supplied will

decrease and the machine will supply leading reactive power

53. In the phasor-diagram of a round-rotor synchronous generator the voltage

equation is t t a a sE V I r jX , where

tE = excitation voltage, tV terminal

voltage; Ia= armature current at lagging power factor ra=armature resistance; Xs = synchronous reactance. While remaining synchronized to the bus-bars (infinite bus), if the power input from the prime mover is gradually decreased and finally stopped, it will result in a. Reversal of Ia, and Et lagging Vt b. Reversal of Ia, but Et leading Vt c. The sign of Ia remaining unchanged,

but Et leading Vt d. The sign of Ia remaining unchanged,

but Et lagging Vt 54. A3-phase induction motor has a full-load

slip of 3 percent at normal voltage. Which one of the following will be the value or the slip of the motor if it de3velops the same torque theoretically while operating at 110 per cent of its normal voltage? a. 2.48% b. 0.248% c. 0.483% d. 4.83%

55. A-6-pole, 3-phase, 60Hz induction motor runs at 1000 rpm developing maximum torque. Rotor resistance per phase is1.2 ohms. Neglecting stator impedance, then for developing maximum torque, the external resistance to be connected in series with each rotor phase will be a. 7.2 ohms b. 6ohms c. 1.44 ohms d. 1.2 ohms

56. The capacitor-start single-phase induction motor develop much larger starting torque in comparison with the “spilt-phase” motor, because the use of capacitors in the auxiliary Winding enables a. Provision of larger number of turns in

the auxiliary winding b. A larger starting current to be drawn

from the supply c. The torque-slip characteristic in

general to get a shape to give a large starting torque

d. The current division between the main and auxiliary windings to be conductive for the development of large starting torque

57. If the load of a synchronous motor is increased while keeping the field excitation constant, then a. Power factor will increase and power

angle will decrease b. Power factor will decrease and power

angle will increase c. Both power factor and power angle

will increase d. Both power factor and power angle

will decrease 58. a synchronous motor operates as a

synchronous condenser when it is a. Operated at unity power factor b. Under-excited c. Over-excited d. Connected in parallel with condensers

59. An equipment has 0.8 per unit impedance on base on 66KV, 100MVA. Its per unit impedance on a base of 33KV, 100MVA will be a. 0.4 b. 0.8 c. 1.6 d. 3.2

60. In a 3-phase power transformer, 5-timbed construction is adopted to a. Suppress the 5th and 7th harmonics b. Suppress the 3rd and its multiple

harmonics c. Suppress all the orders of harmonics d. Increase the capacity of the

transformer 61. A transformer has a resistance of 2% and

reactance of 4%. Its regulations at 0.8 power factor lagging a leading respectively are a. 4 percent and -0.8 percent b. -4 percent and 0.8 per cent c. -0.8 percent and 4 percent d. 0.8 percent and -4 percent

62. Consider the following statements: The use of Delta-connected tertiary windings in star-star connected power transformers 1. Makes available supply for single-

phase loads. 2. Suppresses harmonic voltages. 3. Allows flow of earth fault current for

operation of protective devices.

8 of 144. Provides low-reactance paths for zero-

sequences corrects. Of these statements: a. 1,2 and 3 are correct b. 1,3 and 4 are correct c. 2 and 4 are correct d. 1,2,3 and 4 are correct

63. If dv

dtoccurring across a thyristor exceeds

its permissible value then the thyristor will a. Remain in the forward blocking state

without and damage b. Turn of only to get damaged c. Turn on but whether it gets damaged or

not will depend on the final follow up currents

d. Not turn of but get damaged 64. Which one of the following is necessary

for a triggering system for thyristors in a line commentator converter? a. It must use separate power supply b. It should provide a train of pulses c. It should be synchronized with the

mains supply providing a singe pulse of suitable value

d. It should be synchronized with mains providing a train of pulses

65. The average load current of a dc chopper feeding a pure resistive load is I amps. If a variable inductance connected in the load circuit is progressively increased form zero value, keeping the duty ratio unchanged, then the average load current will a. Increase starting from I b. Decrease with a starting Value of I c. Remain the same at I d. Increase to some highest value of

current and then decrease again to I 66. Consider the following statements:

The source inductance of an ac to dc line commutated phase controlled converter

1. Limits dv

dtcompatibility of thyristors.

2. Causes a voltage drop in the dc terminal voltage.

3. Improves the line side power factor 4. Limits the range of firing angles. 5. Reduced the line side power factor. Of these statements: a. 1,3 and 4 are correct b. 1,2 and 4 are correct c. 2 and 5 are correct d. 2,4 and 5 are correct

67. In the chopper circuit given below, E=220 V, L=1mH, R = 0.25 , EL= 22V,T = 2500 sec Ton 1000 sec. The value of Ton for which the current becomes discontinuous is

a. 332.5 sec b. 33.25 sec c. 665 sec d. 66.5 sec

68. A single-phase voltage controller is employed for controlling the power flow form 260 V, 50Hz source into a load consisting of R = 5 and L=12 . The value of maximum rms load current and the firing angle are respectively

a. 260

10.9A and 0°

b. 20 A and 0° c. 20A and 90°

d. 260

10.9A and 90°

69. In sinusoidal PWM, there area m cycles of the triangular carrier wave, in the half cycle of reference sinusoidal single. If the zero of the reference sinusoid coincides with the zero of the triangular carrier wave, then the number of pulse of generated in each half cycle is a. m/(m-1) b. (m+1)/(m-1) c. 1 d. (m-1)/m

70. The number of thyristors required for single phase to single phase cycloconverter of the mid-point type and for three phase phase to three-phase 3- pulse type cycloconverter are respectively a. 4 and 6 b. 4 and 4 c. 4 and 18 d. None of the above

71. Match List I (Drive) with List II (Speed control range) and select the correct answer using the codes given below the lists: List I

9 of 14a. Square wave inverter-fed induction

motor b. PWM inverter-fed induction motor c. Slip energy recovery scheme with

cycloconverter in the rotot circuit d. Cycloconverterfed induction motor List II 1. 50% of synchronous speed to

synchronous speed 2. 10% of base speed to beyond base

speed (1:20) 3. 0 to 1/3 base speed 4. 67% of synchronous speed to 133% of

synchronous speed zero to 150% of base speed (1:infinity)

Codes: A B C D a. 2 5 4 3 b. 2 5 3 4 c. 3 2 4 1 d. 3 2 1 4

72. In which one of the following models of transmission lines, is the full charging current assumed to flow over half the length of the line only? a. Equivalent- b. Short line c. Nominal - d. Nominal -T

73. If the receiving-end voltage and current are numerically equal to the corresponding sending-end values, that is |Vs|=|VR+| and |Is|=|IR|, then such a line is called a. An infinite line b. A natural line c. A tuned line d. A loss-less line

74. The convergence characteristics of the Newton-Rophson method for solving a load flow problem is a. Quadratic b. Liner c. Geometric d. Cubic

75. If |Vs|=|VR| = 66kV for three –phase transmission and reactance is 11 ohms/phase, then the maximum power transmission per phase would be a. 132MW b. 396MW c. 66MW d. None of above

76. For a two-machine system with losses, with the transfer impedance being

resistive, the maximum value of the sending end power P1max and the maximum receiving –end power P2 max will occur at power angle ( ) in such a manner that a. Both P1max and P2 max occur at <90° b. Both 1 max and P2 max occur at >

90° c. P1 max occur at >90° and P2 max <

90° d. P1 max occur at < 90° and P2 max at

< 90° 77. Consider the following expression:

1 2V f x rt f x rt

Where f1 and f2 represent two traveling waves on a transmission line. In this case a. Both waves travels in the positive

direction of x b. Both waves travel in the negative

direction of x c. Wave f2 travels in the positive

direction of x but wave f2 travels in the negative direction of x

78. For reducing tower foot in resistance, it is better to employ a. Chemical and counterpoise b. Chemical and ground rods c. Ground rots and counterpoise d. Chemical, gou8nd rods and

counterpoise 79. A suspension type insulator has three units

with self-capacitance C and ground capacitance of 0.2 C having a string efficiency of a. 78% b. 80% c. 82% d. 84%

80. A bulled conductor line compared to a single conductor line (With same conductor cross-sectional area and same meant distance between conductors) has

Self GMD Mutual GMD Per phase inductance

a. Lower Nearly same Higher b. Higher Lower Nearly same c. Higher Nearly same Lower d. Lower Higher Higher 81. In a 14-bus power system network, three

are 5 voltage controlled buses. The size of the jacobiam matrix useful for power flow analysis will be a. 16 × 16 b. 23 × 23

10 of 14c. 21 × 21 d. 8 × 8

82. A thyrite lighting arrester has a. Inverse resistance characteristics b. A gap c. Efficient earthling d. A combination of inverse resistance

characteristics and gap 83. Differential protection of a generator

makes use of the principal that under normal conditions, the current/currents a. At the neutral end of a phase winding

is zero b. In each of the phase winding is

identical c. At both ends of the phase winding are

equal d. At the two ends of the phase winding

are unequal the reactance relay is essentially

84. The reactance realy is essentially a. An over-voltage realy with current

restraint b. An over-current realy with

directionally restraint c. A directional realy with voltage

restraint d. A directional realy with current

restraint 85. Severe over-voltages are produced during

arcing faults in a power system with the neutral a. Isolated b. Solidly Earthed c. Earthed through a low resistance d. Earthed through an inductive coil

86. In HVCD transmission system, rectifier firing angle is kept near a. 0° b. 15° c. 30° d. 90°

87. A two-bus system is shown in the given figure. When 100 MW is transmitted from plant 1 to the load, the transmission loss is 10MW. The incremental; fuel costs of the

two plants are 11

1

0.02 16dc

PdP

and

22

20.04 20

dcP

dP .

The optimum distribution of total load of 260 MW between the two plants when losses are included but not coordinated is

P1 P2

a. 300MW 50MW b. 240MW 20MW c. 130MW 130MW d. 220MW 60MW

88. Assertion (A): The system with transfer function

10 12

2 3

sG s

s s s

Reason (R): It has a zero on the right half of the s-plane. a. Both A and R are true and R is the

correct explanation of A b. Both A and R are true but R is not a

correct explanation c. A is true bur R is false d. A is false but R is true

89. Assertion (A): The closed-loop system represented in the given figure is a type -1 system.

Reason (R): Number of poles at the origin

possessed by the feedback path decides the type of the closed-loop system a. Both A and R are true and R is the



90. Assertion (A): Data acquisition systems are widely used in a variety industrial and scientific areas. Reason (R): Data acquisition systems often use magnetic tape recorders. a. Both A and R are true and R is the



91. Assertion (A): In fivre optic communication, the 1,3 m , window is

11 of 14preferred over the 0.85 m window for long distance communication. Reason (R): At 1.3 m not only the attenuation of silica fiber is lower than that at 0.85 m , the pulse broadening at the long wavelength window is also minimum. a. Both A and R are true and R is the



92. Assertion (A): For transmitting audio frequency signals, antennas of several hundred kilometers length would be required. Reason (R): For efficient radiation of electromagnetic energy to occur from an antenna, the wavelength of the radiated signal must be comparable with the physical dimensions of the antenna. a. Both A and R are true and R is the



93. Assertion (A): In a high frequency transmission line, when a voltage is placed across the line at the sending end, the voltage and current in the line change with distance. Reason (R): A transmission line consists of continuous conductors with a cross-sectional configuration that is content throughout their lengths. a. Both A and R are true and R is the



94. Assertion (A): MOSFET RAMs are usually slower than bipolar RAMs. Reason (R): MOSFET RAMs in comparison with bipolar RAMs can be fabricated in much larger capacity in a single IC and consume much less power. a. Both A and R are true and R is the



95. Assertion (A): A BJT amplifier needs very good bias stabilization circuit as compared to that of an FET amplifier circuit. Reason (R): The input p-n junction of FET amplifier is reverse biased and that of the BJT amplifiers forward biased. a. Both A and R are true and R is the



96. Assertion (A): A monostable multivibrator can be used as a counter. Reason (R): The pulse width of the monostable multivibrator is a function of its input dc voltage. a. Both A and R are true and R is the



97. Assertion (A): For a periodic inpu8t voltage whose amplitude is large enough to pass through the trip points, a Schmitt trigger produces a rectangular wave-form at the output. Reason (R): A Schmitt trigger is a comparator with positive feedback and hence prevents noise triggering. a. Both A and R are true and R is the



98. Assertion (A): The multistage intermediate frequency amplifier of superheteroyne radio receiver is always staggered tuned. Reason (R): A very sharp tuned high gain amplifier is obtained maximizing the gain and increasing the fidelity of the receiver. a. Both A and R are true and R is the



99. Assertion (A): Three-phase transformers of different vector groups should not be operated in parallel.

12 of 14Reason (R): Transformers belonging to different vector groups will not have the same phase sequence on the secondary side. a. Both A and R are true and R is the



100. Assertion (A): In a 3-phase induction motor, the stator is to be wound for 4 poles but by mistake, the rotor is wound for 2 poles only. When the stator is fed from a 50Hz, 3-phase supply with rotor winding shorted, the motor does not start up. When however, the wound rotor is replaced by a squirrel-cage rotor, the machine operates without any problem. Reason (R): Rotor of an induction motor should not have any poles. a. Both A and R are true and R is the



101. The current I1 through the 5 resistor in the network shown in the figure, is

a. 8.58 A b. 7.54 A c. 11.66 A d. 14 A.

102. A lamp rated at 10watts, 50 volts is proposed to be used in 110 volts, system. The wattage and resistance of the resistor to be connected in series with lamp should be a. 15 watts, 350 ohms b. 1o watts, 250 ohms c. 12 watts, 300ohms d. 15 watts, 250 ohms

103. Match List I with List II and select the correct answer using the codes given below: List I A. Superaposition theorem B. Thevenin theorem

C. Signal flow graph D. Complex frequency List II 1. Current source 2. linearity 3. s-plane 4. mason’s gain formula 5. Voltage source

A B C D a. 2 1 4 5 b. 1 2 4 5 c. 2 5 3 4 d. 2 5 4 3

104. Thevenin’s equivalent resistance Rth for the network shown in the given figure is known to be 2 . The value of R in ohms is

a. 1 b. 2 c. 3 d. 4

105. The driving-point impedance of the network shown in the figure is given by

a.

4 3 / 2

5 / 4

s

s

b.

3 / 2

5 / 4

s

s

c.

5 / 4

3 / 2

s

s

d.

3 / 21

4 3 / 2

s

s

106. The correct value of the current I (t) at any instant when K is switched on at t = 0 in the network in the given figure is

13 of 14

a. /R L tE Ee

R R

b. /E E

e R L tR R

c. /R L tE Ee

R R

d. /R L tE Ee

R R

107. For the given tow-port network, Z21 will be

a. 2/5 b. 3/5 c. 1/5 d. 4/5

108. If the driving-point admittance function of

a 1-port network is KsY s

s

, it can be

realized using a. Series combination R,L b. Parallel combination of R,L c. Series combination of R,C d. Parallel combination of R,C

109. The pole-zero plot of a network function H(s) is shown in the given figure. Which one of the following will be the correct nature of its frequency response plots?

a. The amplitude plot will decay with

frequency but the phase plot will be constant at all frequencies

b. The amplitude plot will be constant but the phase plot will vary from +180° to

+90° as frequency varies from zero to infinity

c. The amplitude and phase plots will be consent at all frequencies

d. The amplitude plot will be constant but the phase plot will vary form +180° to 0° s the frequency varies from zero to infinity

110. In a series resonant circuit, which one of the following will increase on increasing the inductance to four times its value and reducing the capacitance to one-fourth of its value? a. Resonant frequency b. Current at resonant frequency c. Impedance at resonant frequency d. Selectivity of the circuit

111. A series RLC circuit draws current at leading power factor at a. The resonant frequency b. Frequency less than the resonant

frequency c. Frequencies more than the resonant

frequency d. Frequencies both less and more than

the resonant frequency 112. One of the two wattmeter has read zero in

the two-wattmeter method of power measurement. This indicated that the load phase angle is a. 0° b. 30° c. 60° d. 90°

113. In the circuit shown in the given figure, three-phase supply is connected to a star-connected load. If ammeters A1, A2, A3 read 12.5 A, what will be the reading of ammeter AN?

a. 37.5A

b. 37.5

3A

c. 37.5 3A d. Zero

114. For the circuit shown in the given figure, if R = 10 , XL=0.1 and Xc=0.1 , then the fur rent through R is

14 of 14

a. 0 b. 10I c. I d. 0.11

115. Two coupled coils have L1 = 0.6 H, L2=0.6H and coupling coefficient = 0.25. coil 2 has 800 turns. If current I1 in coil is 6sin 100t amps, then the voltage across coil 2 is a. 90cos 100t volts b. 9cos 100t volts c. 0.9cos 100t volts d. 0.09cos 100t volts

116. If a charge of one coulomb is to be brought to a distance of one meter from a charge of 2 coulomb, then the work required is

a. 0

1

2N m

b. 0

1

4N m

c. 02 N m

d. 04 N m

117. A small permanent magnet makes small oscillations in a uniform magnetic field as shown in the given figure. The period of oscillations is T. if the strength of the magnetic field is doubled, the period of oscillations will be

a. 2T

b. 2T

c. / 2T d. T/2

118. A uniform plane electromagnetic wave with electric component E = Em cos t px propagates in vacuum along the

positive x-direction. The mean pointing vector is given by

a. 2 20

1/

2 mc E

b. 2 20

1/

2 mc E

c. 0

1/

2 mcE

d. 20

1/

2 mc E

119. Match List I (Antemma) with List II (Application/Characteristics) and select the correct answer using the codes given below the lists: List I A. A quarter wave monopole over ground

plane B. A vertical half-wave dipole C. Folded dipole D. Hertzian dipole (length< 100) List II 1. radiation resistance <<1 2. radio broadcast 3. omni directional pattern 4. TV reception Codes:

A B C D a. 2 3 4 1 b. 2 3 1 4 c. 3 4 1 2 d. 3 4 2 1

120. In respect of a rectangular wave-guide of dimension a × b, match List I (Mode) with List II (Cut-off wavelength) and select the correct answer using the codes given below the lists: List I A. TE0,1 B. TE1,0 C. TE2,0 D. TE1,1 List II 1. 2a 2. 2b

3. 2 2

2ab

a b

4. a 5. b

A B C D a. 2 1 3 4 b. 2 1 4 3 c. 4 5 3 1 d. 4 5 1 3

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1. The mean square value of the shot noise

current a. Varies inversely as average current b. Is independent of average current

c. Varies as average current

d. Varies directly as average current 2. The characteristic impedance of an air

dielectric coaxial line is 77 . If the air is replaced by a dielectric with r =2.28, the

characteristic impedance will be a. 33.8 b. 51 c. 116 d. 175

3. In India, the maximum frequency deviation in commercial FM broadcasting signals is about a. 5 kHz b. 15 kHz c. 75kHz d. 200kHz

4. The core diameter of a step index optical fibre rages form a. 300 m to 500 m b. 300 m to 500mm c. 300 nm to 40 nm d. 2 m to 200 m

5. In a Mesh topology of communication network. If there are N stations, the total number of possible full duplex links is a. N – 1 b. N (N – 1)

c. 1

2

N N

d. 1

2

N

6.

The type of modulation of the arrangement shown in the above figure is a. ASK b. FSK

c. OOK d. PSK

7. If the antenna diameter in a radar system is increased by a factor of 4, the maximum range will be increased by a factor of

a. 2 b. 2 c. 4 d. 8

8. Consider the following features regarding satellite communication: 1. Height of satellite. 2. Downlink frequency 3. Gain of transmitting antenna 4. Gain of receiving antenna The free space transmission loss depends on a. 1 and 3 b. 1 and 2 c. 2 and 3 d. 3 and 4

9. The magnetic field intensity H in A/m, at

the point (0,0,2) due to a current sheet K =

8 xa A/m lying in the z = 0plane is

a. 2 ya

b. 8 ya

c. 4 ya

d. ya

10. An infinitely long dielectric cylinder of relative permittivity, r is placed in air in a

uniform electric field of magnitude E directed perpendicular to its axis. The stress within the cylinder is

a. 2

1 r

E

b. 2

1 2 r

E

c. 3

2 r

E

d. 2

1r

r

E

11. If the E field in a plane electromagnetic wave traveling along the z-axis is given by

C.S.E Pre-2000


2 of 15

x y x yE a a f t z a a f t z

The H field associated with the wave is (z0 is the characteristic impedance)

a. 0 0x y x ya a f t bz z a a f t bz z

b. 0 0/ /x y x ya a f t z z a a f t z z

c. 0 0/y x y xa a f t z z a a f t z z

d. 0 0/ /x y y xa a f t z z a a f t z z

12. Values of VSWR measured by terminating

the load end of a transmission line first with horn, then with a show and finally with a matched load, will be respectively a. 20,1.9 and 1.01 b. 20,1.01 and 1.9 c. 1.9,1.01 and 20 d. 1.9, 20 and 1.01

13. In an 8085 microprocessor, the accumulator contents get altered by the instruction a. ANI 5 C b. CMP C c. CPI 3A d. ORA A

14.

In the above network, if IR = (4e-3t+3e-4t) A and iL (0) = 1 A, then

would be equal to a. / 2 b. /3 c. /4 d. /6

15.

It Thevenin’s equivalent resistance of the above circuit seen from the open terminal is 2 , then the value of ‘R’ will be a. 4 b. 2

c. 1 d. Zero

16. Match List I (Pole position) with List II (Response) and select the correct answer using the codes given below the lists: List I

List II

A B C D

a. 3 4 2 1 b. 4 3 1 2 c. 3 4 1 2 d. 4 3 2 1

17. The above network contains two passive elements. If the response to a step voltage input u(t) is i(t) = e-3t A, then network ‘N’ contains

a. An R = 1 and an 1

3L H in series

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b. An R=1 and an 1

3L H in parallel

c. An R = 1 and a 1

3C F in parallel

d. An R = and a 1

3C F in series

18. The Laplace transform of current in an RLC series circuit with

12 , 1

2R L H and C F is

2

1

2 2I s

s s

The voltage across the inductor ‘L’ will be a. sinte t u t

b. coste t u t

c. sin coste t t u t

d. cos sinte t t u t

19. The Fourier transform of unit impulse function t would be

a. 2

1

2

b. 22

c. 1

d. 1

2

20.

The y-parameter ‘y21’ of the above network a. Is 12 mho b. Is 6 mho c. Is 3 mho d. Does not exits

21. The response of system is expressed by 2

2.

d ii v

dt it the excitation is 2tv ke , then

the forced response of I for t>0 will be

a. 3

tke

b. 5

tke

c. 2

5tk

e

d. sin cos3 5

k kt t

22. The phasor current through the inductance in the above circui9t shown is

a. 10

452

b. 10

452

c. 5 45 d. 5 45

23. The maximum value of mutual inducatance of two inductively coupled coils with self-inductance L1 = 49mH and L2=81 mH is a. 130 mH b. 63mH c. 32mH d. 3969 mH

24. The resonant frequency of a series RLC circuit is 1.5 MHz with the resonating capacitor set at 150 pF. If the bandwidth is 10 kHz, then the effective resistance of the circuit would be approximately a. 29.5 b. 14.75 c. 9.4 d. 4.7

25. Consider the difference equation of LTI causal discrete time system

3 11 2

4 8y n y n y n x n

The impulse response of the system is

a. 1 12

2 4

n n

u n

b. 1 12

2 4

n n

u n

c. 1 12

4 2

n n

u n

d. 1 12

4 2

n n

u n

26. The low frequency gain of the low pass filter shown in the above figure is

4 of 15

a. 10 dB b. 20dB c. 30dB d. 40 dB

27. The system y(t) = tx (t) + 4 is a. Non-linear, time-varying and unstable b. Linear, time-varying and unstable c. Non-linear, time-invariant and unstable d. Non-linear, time-varying and stable

28. Consider the following statements about the z-transform, X(z) of the sequence

2 0

0 0

nx n for n

for n

(ROC denotes region of convergence in the z-plane)

1. 1

1:| | 2

1 2X z ROC z

z

2. 1

1

21 :| | 2

1 2

zX z ROC z

z

3. 1

1:| | 2

1 2X z ROC z

z

Which of these statements are correct? a. 1 and 3 b. 1 and 2 c. 2 and 3 d. 1,2 and 3

29. A signal of bandwidth 4 kHz is recorded in a tape recorder at normal speed. If for transmission purposes, the recorder is replayed at 4 times the normal speed, then the transmission bandwidth will be a. 16 kHz b. 8 kHz c. 4 kHz d. 1 kHz

30.

Which one of the following statements regarding the function whose plot is shown in the above figure, is NOT correct?

a. It has a dc value of b. It has a period of 2s c. Its fundamental component has the

magnitude 2 d. It contains only even harmonics

31. In LED, light is emitted because a. Recombination of charge carriers takes

place b. Diode gets heated up c. Light falling on the diode gets

amplified d. Light gets reflected due to lens action

32. For any amplifier configuration using a BJT, the input impedance Ri is

a. 1i feh h

b. 1 r V

h

h A

c. 11i

V

h

h A

d. 1

i

fe

h

h

33.

Frequency response characteristic of a single-stage RC coupled amplifier is shown in the above figure. The fall in gain at both ends of the characteristic is due to a. Transistor shunt capacitances b. Bypass and coupling capacitances of

the circuit c. Transistor shunt capacitances at the

lower end and bypass and coupling capacitances at the higher end

d. Transistor shunt capacitances at the higher end and bypass and coupling capacitances at the lower end

34. Match list I (Circuit) with List II (Type of connection) and select the correct answer using the codes given below the Lists. List I

5 of 15

List II

1. Darlington 2. Cascade 3. Parallel 4. Casocode

A B C D a. 4 3 1 2 b. 3 4 2 1 c. 3 4 1 2 d. 4 3 2 1

35. The op-amp shown in the above circuit has an imput impedance of 1M and an open-loop gain of 105. The input impedance seen by the source vs is

a. 1110 b. 1010 c. 10k d. 1k

36. The gain of a negative feedback amplifier is 40 dB. If the attenuation of the feedback path is 50 dB, then the gain of the amplifier without feedback is a. 78.92 b. 146.32 c. 215.51 d. 317.23

37. The following table provides a comparison of the performances of common base (CB), common emitter (CE) and common collector (CC) configurations of a transistor:

Parameter CB CE CC 1. Input impedance

Low Medium High

2. Current gain High Low High 3. Voltage gain >1 >1 <1

In this table, the performances of CD, CE, and CC have been correctly indicated in respect of parameters a. 1,2 and 3 b. 1 and 2 c. 2 and 3

d. 1 and 3 38.

The op-amp circuit shown in the above figure is a a. Precision half-wave rectifier b. Precision full-wave rectifier c. Peak detector d. Level shifter

39.

The kamugh map of a Boolean function is shown in the above figure. The simplified function is a. AB+CD+BD’ b. B’D’+B’C’+A’C’ c. (A’+B’)(C’+D’)(B’D’) d. (A+B’)(C+D’)(B+D’)

40. Which one of the following statements is not correct? a. If everything else is equal, then a 10 bit

digital ramp ADC will have a better resolution but a longer conversion time than an 8 bit ADC

b. The conversion time for a successive approximation increases with the increase in input voltage

c. A flash ADC does not contain a DAC d. VCO is the main component of a

voltage to frequency ADC 41. Consider the following data in respect of a

certain digital gate 0.2 , 16 , 40 1.6OH OL IH ILI mA I mA I A and I mA

The symbols have their usual meanings. The ‘fanout’ will be a. 80 b. 40 c. 10 d. 5

42.

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For the JK flip-flop shown in the above figure, J=Q and K= 1. If it is initially cleared and then clocked for 6 pulses, the sequence at the Q-output will be a. 010101 b. 010000 c. 011001 d. 010010

43. A full adder circuit may be constructed by using a. Two 2-input AND gates and two 3-

input OR gates b. Two half adders and a 2-input AND

gate c. Two half adders and a 2-input OR gate d. Two 2-input AND gates and two 3-

input XOR gates 44. If (211)X = (152)8 then the value of base x’

is a. 3 b. 5 c. 7 d. 9

45. The range of numbers that can be represented in two’s complement mode with four binary digits is a. –15 to + 15 b. –8 to +8 c. –8 to +7 d. –7 to + 7

46. Given that N is the actual number of instructions executed and CPI is the average number of cycles per instruction, then a. Both CISC (Complex instruction set

computer) and RISC (Reduced instruction set computer) processors aim to reduce N at the expense of CPI

b. CISC processors aim to reduce N at the expense of CPI whereas RISC processors aim to reduce CPI at the expense of N

c. RISC processors aim to reduce N at the expense of CPI whereas CISC processors aim to reduce CPI at the expense of N

d. Both CISC and RISC processors aim to reduce CPI at the expense of N

47. Cycle time of a Random, Access Memoir is the time required between successive a. Accesses to memory b. Clocks c. Delete operations d. Read/Write operations

48. The INTEL 8080 microprocessor has a set of 91 instructions. The op-code to implement this instruction set should be of at least a. 6 bits b. 4 bits c. 7 bits d. 8 bits

49. Consider the following assembly language code for a simple computer having one register only. LOAD X ADD Y STORE Ti STORE T2 MULT Z MULT Ti ADD T2 STORE R Which one of the following arithmetic expression does it evaluate?

a. 22: . 1R Z X Y

b. 22: .R Z X Y X Y

c. 2 2: .R Z X Y X Y

d. 2: .R Z X Y X Y

50. Consider the following statements regarding a ‘smart’ terminal: 1. It is a minimal system containing

almost no memory. 2. It contains a small microcomputer or

minicomputer. 3. It permits text editing. 4. It enables checking of typing errors

made by operations. Which of these statements? a. 1,2 and 3 b. 1, 2.and 4 c. 2, 3 and 3 d. 1, 3 and 4

51. Match List I (Signal flow graph) with List II (Transfer function) and select the correct answer using the codes given below the lists: List I

7 of 15

List II

1. 1

P

Q

2. 1

Q

PQ

3. 1

Q

PQ

4. 21

PQ

P

A B C D a. 2 3 4 1 b. 2 3 1 4 c. 3 2 1 4 d. 3 2 4 1

52. The unit step response of a second order Imear system with Zero initial states is given by The damping ratio and the undraped natural frequency of oscillation of the system are respectively a. 0.6 and 10 rad/s b. 0.6 and 12.5 rad/s c. 0.8 and 10 rad/s d. 0.8 and 12.5 rad/s

53.

Consider the following statements

regarding the transfer function G(s) plotted in the above figure. 1. G(s) has corner frequencies at =0.1,1

and 10.

2.

100 1

10

sG s

s s

3. The magnitude of 20 log10 | |G j at

=1000 is -20 dB.

Which of these statements are correct? a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

54. The Nyquist polar plot of a system with

; 0,

s zG s H s p

s s p

is

represented as

55. Type of a system depends on the

a. Number of its poles b. Difference between the number of

poles and zeros c. Number of its real poles only d. Number of poles its has at the origin

56.

The above figure shows root-loci of open loop transfer function G(s) H(s) of a system. Consider the following inferences drawn from this figure 1. It has no zero. 2. It is a stable system. 3. It is a second order system. Which of these inferences are correct? a. 1, 2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

57. The Nyquist plot of a closed-loop system is shown in the above figure. The plot Indicates that the

8 of 15

58. Which one of the following statements

regarding the state transition matrix is correct? a. 0 0

b. 1 1t

t

c. 1 2 1 2t t t t

d. 2 1 1 0 2 0t t t t t t

59. The final value of function

2

5

2F s

s s s

is equal to

a. Zero

b. 2

5

c. 5

2

d. 5 60. Consider the following statements:

1. P-D controller is equivalent to a high pass filter.

2. For better performance, integral action is initiated before derivative action.

3. High proportional gain s an alternative to derivative action.

4. A practical PID controller uses a high gain amplifier in the forward path.

Which of these statements are Not correct? a. 1, 2 and 4 b. 2, 3 and 4 c. 2 and 3 d. 1 and 4

61.

If the bridge shown in the above figure is balanced, then the value of the inductance ‘L’ will be a. 100 mH b. 20 mH

c. 2 mH d. Dependent on supply frequency

62. Two sinusoidal signals of frequency f and 3f are applied as x and y inputs respectively to an oscilloscope. Which one of the following patterns could be observed on the screen?

63. In measuring the distributed capacitance

Cd’ of a certain coil using Q-meter, initial resonance at frequency 2 MHz is obtained by tuning the capacitance set to 430 pE. If resonance at 4 MHz is obtained by tuning the capacitance set to 100 pE. then the value of ‘Cd’ would be a. 10 pF b. 20 pF c. 100 pF d. 200 pF

64.

Above figure shows the input attenuation of a millimeter. If the meter reads full-scale with 10 V at M with the range switch at position p’. then the required voltage at M to obtain full-scale deflection with the range switch at position r will be

a. 10 V b. 200 V c. 100 V d. Undeterminable because resistance of

the dc probe is not known. 65. Match List I (Measurements) with List II

(Transduction principles) and select the correct answer using the codes given below the List: List I A. rpm

9 of 15B. Temperature C. Static pressure D. Current List II 1. Variable resistance 2. Hall effect 3. Piezoelectric effect 4. Variable reluctance 5. Variable capacitance

A B C D a. 4 1 5 2 b. 1 4 5 2 c. 2 1 3 5 d. 4 1 2 5

66. A resistance strain gauge with a gauge factor of 2 is fastened to a steel member subjected to a stress of 10.5 × 104 kN/ m2. The modulus of elasticity of steel is 2.l× 108 kN/m2. The change of resistance due to stress in the strain gauge is a. 0.1% b. 0.2% c. 1% d. 10%

67. How many comparators are there in an ADC with 0–5 V input and 8 bit output assuming a flash converter? a. 5 b. 8 c. 40 d. 255

68. Given that = Polaris ability N = Number of dipoles /m2

r =Relative dielectric constant and

0 dielectric constant of free space, the

clausius mossoti relation is

a. 0

1

1 3r

r

N

b. 0

1

2 3r

r

N

c. 031

2r

r N

d. 031

1r

r N

69. The ratio of the electrical resistance of a material at 300 K to its electrical resistance at 4 K is 5. This material could be a. An intrinsic semiconductor b. An extrinsic semiconductor c. An insulator d. A conductor

70. Consider the following statements in respect of Y Ba2Cu3O7-x superconductor 1. It has poor formability. 2. Its superconducting property is very

sensitive to humidity and temperature. 3. Its application requires a constant

supply of liquid helium. Which of these are the difficulties in the exploitation of the given superconductor for engineering use? a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

71. In a ferromagnetic material, the magnetic field is increased gradually from zero. The first process which sets in the material to give net magnetization is the a. Growth of favorably oriented domains

at the cost of other domains by reversible domain wall movement

b. Growth of favorably oriented domains at the cost of other domains by irreversible domain wall movement

c. Alignment of domain walls with the grain boundaries

d. Rotation of domains in the direction of the applied field

72. If two semiconductor specimen have carrier concentration ‘n1’ and n2’ and their Hall coefficients are ‘R1 and ‘R2

respectively, then

a. 1/2

1 1

2 2

R n

R n

b. 1 1

2 2

R n

R n

c. 1 2

2 1

R n

R n

d. 1/2

1 2

2 1

R n

R n

73. Consider the following statements As compared to Si single crystal grown by the CZ method, the Si single crystal grown by the FZ method should have 1. Lesser oxygen contamination. 2. Uniform doping throughout the length

of the crystal. 3. More substitution carbon atoms in the

crystal. Which of these statements are correct? a. 1, 2 and 3 b. 1 and 3

10 of 15c. 2 and 3 d. 1 and 2

74. For the epitomical growth of material M to be possible on the substrate of material N, a. The lattice constants of M and N must

be same b. M and N must not react with each

other c. The coefficients of thermal expansion

of M and N must be equal d. M must have a lower density than N

75. Silicon nitride is used as the passivating cover layer in MOS technology because it is a. Easy to deposit b. Resistant to oxidation c. An excellent barrier to alkali ions d. An excellent mask for gallium

76. The economizer. a component of steam power plants, is a heat-exchanger utilizing the waste heat of a. Bleed-steam to heat the feed water b. Flue-gas to heat the feed water c. Flue-gas to heat the air going into the

boiler d. Flue-gas to heat the pulverized coal

77. Consider the following statements about the utility of delta-connected tertiary windings in star-star connected power transformer currents. 1. It makes supply available for small

loads. 2. It provides low reactance paths for

zero sequence 3. It is used to suppress harmonic

voltages. 4. It is used to allow flow of earth fault

current for operation of protective relays.

Which of these statements are correct? a. 1 and 2 b. 2,3 and 4 c. 1,3 and 4 d. 1,2,3 and 4

78. A 3-phase transmission line conductors were arranged in horizontal spacing, with ‘d’ as the distance between adjacent conductors. If these conductors are rearranged to form an equilateral triangle with sides equal to ‘d’, then the a. Capacitance and the inductance will

increase b. Capacitance will increase and the

inductance will decrease

c. Capacitance and the inductance will remain the same

d. Capacitance will decrease and the inductance will increase

79. The inductance per unit length of an overhead line due to internal flux linkages a. Depends on the size of the conductor b. Is independent of the side of conductor

and constant c. Depends on the current through

conductor d. Depends on distance between

conductor

80.

A single-phase ac distributor supplies two single-phase loads as shown in the above figure. The voltage drop from A to C is, a. 4.5 + j 30 V b. 30 + j 4.5 V c. 4.5 – 30 V d. j 30 V.

81. A synchronous generator with synchronous reactance of 1:3 Pu IS connected to an infinite bus whose voltage is 12 pu, through an equivalent reactance of 0.2 pu. For maximum output of 1:2 pu, the alternator emf must be a. 1.5 Pu b. 1.56 pu c. 1.8 pu d. 2.5 pu

82. Consider the following statements Transient stability limit of a synchronous generator feeding power to an infinite bus through a transmission line can be increased by 1. Increasing the steam supply to tubine

driving the generator during fault clearing.

2. Connecting resistors at the generator terminals during fault condition.

3. Employing a faster excitation system. 4. Quickly throwing off the generator

load. Which of these statements are correct? a. 2 and 3 b. 3 and 4 c. 1 and 2

11 of 15d. 2 and 4

83. An overhead transmission line having surge impedance ‘Z1’ is terminated to underground cable o surge impedance Z2’. The reflection coefficient for the traveling wave at the junction of the line and cable is

a. 1 2

1 2

Z Z

Z Z

b. 2

1 2

Z

Z Z

c. 2 1

1 2

Z Z

Z Z

d. 1 2

1 2

Z Z

Z Z

84. Ring main distribution is preferred to a radial system because a. Voltage drop in the feeder is less and

supply is more reliable b. Voltage drop in the feeder is less and

power factor is high c. Power factor is high and supply is

more reliable d. Power factor is high and system is less

expensive 85. If the fault current is 3000 A for a relay

with a plug setting of 50% and CT ratio of 1000:1, the plug setting multiplier would be a. 1.5 b. 3 c. 4.5 d. 6

86. Match List I (Protective schemes) with List II (Equipment) and select the correct answer using the codes given below the lists: List I A. Mho relays B. Inverse time over current relays C. Differential relays List II 1. Generators 2. Transmission lines 3. Motors

A B C a. 2 1 3 b. 2 3 1 c. 3 2 1 d. 1 3 2

87. Reversal of power flow in HVDC link by controlling the firing angle simultaneously at both the onverter stations results in a. Reversal of voltage polarity of HVDC

pole b. Reversal of current in dc link c. Reversal of current in dc link as well

as reversal of voltage polarity of HVDC pole

d. Neither reversal of current in dc link nor reversal of voltage polarity of HVDC pole

88. In terms of plant powers PN and Pm, and loss coefficients Bmn the total transmission loss ‘PI ‘ is

a. 1 1

N N

mn nm n

B P

b. 1 1

N N

m mnm n

P B

c. 1 1

N N

m mn nm n

P B P

d. 1 1

2N N

m mnm n

P B

89. The average value of dc voltage of a single-phase semi converter under continuous conduction is

a. 2 2 cosV

b. 2 1 cosV

c. 2 1 cos

2

V

d. 2 1 cos

2

V

90.

The sinusoidal distributed balanced three phase windings shown in the above figure are supplied with balanced three- phase currents,

12 of 155

sin ), sin6 6A m B mi I t i I t

and 5

Imsin6Ci t

At the angular instant ,6

t the value of

angular position ‘ ’ of the rotating mmf ‘F’ with respect to phase A axis will be

a. 2

b. 2

c. 6

d. 6

91. In a loaded dc generator. if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will a. Improve with fall of terminal voltage. b. Deteriorate with fall of terminal

voltage c. Improve with rise in terminal voltage d. Deteriorate with rise in terminal

voltage 92. A dc shunt motor is required to drive a

constant power load at rated speed while drawing rated armature current. Neglecting saturation and all machine losses, if both the terminal voltage and the field current of the machine are halved, then a. The speed becomes 2 pu (per unit) but

armature current remains at 1 pu b. the speed remains at 1 Pu but armature

current becomes 2 Pu c. Both speed and armature current

become 2 pu d. Both speed and armature current

remain at 1 pu 93.

A synchronous motor having a

synchronous speed of 1500 rpm slows down to 1490 rpm due to sudden increase in load on the motor shaft. Assuming a

south pole on the stator near the damper bars labeled 1, 2, 3 and 4 as shown in the above figure, the direction of induced force on conductor 3 is a. F1 b. F2 c. F3 d. F4

94. A 3-phase synchronous motor with negligible losses is connected to the supply at rated frequency and constant terminal voltage ‘V. The induced emf of the motor is designated as E. If the motor is now gradually loaded to its rated power, adjusting its excitation to obtain, say 0.8 leading power factor operation, then E-pharos would a. Be less than V-pharos and also lead V-

pharos b. Be greater than V-pharos and also lead

V-pharos c. Be less than V-pharos and also lag V-

pharos d. Be greater than V-pharos and also lag

V-pharos 95. An alternator of 400 kW is driven by a

prime mover of speed regulation 4% and another alternator of 200 kW is driven by a prime mover of speed regulation 3%. The total load they can take, without overloading either of the machines is a. 600 kW b. 500 kW c. 450 kW d. 400 kW

96. Consider the following statements Modem alternators are designed for large air-gap to have 1. Large inherent regulation. 2. Very stable parallel operation. 3. Higher stability limit. 4. Sinusoidal mmf distribution, Which of these statements are correct? a. 1, 2 and 3 b. 2, 3 and 4 c. 1, 3 and 4 d. 1, 2 and 4

97. When a single-phase capacitor start induction motor is running at a steady speed delivering a fixed torque, then a. Peak of forward rotor mmf is equal to

the peak of backward rotor mmf b. Peak of forward startor mmf is equal to

the peak of backward stator mmf

13 of 15c. Net forward rotating flux is equal to

the net backward rotating flux d. Forward flux produced by rotor current

is equal to backward flux produced by rotor current

98. A 3-phase delta connected squirrel cage induction motor has a starting current of I and a starting torque of T at rated

voltage. If the starting current and starting torque while the motor is started through star-delta starter and auto-transformer (with 60% voltage) starter alternatively, are I.,, and Ty and Iauto and Tauto

respectively, then : : :yauto autoYTI TI

I I T T

is

equal to

a. 1 1

: 0.6 : : 0.63 3

b. 1 1

: 0.6 : : 0.363 3

c. 1 1

: 0.36 : : 0.63 3

d. 1 1

: 0.36 : : 0.3633

99. If a 3-phase induction motor and a 1-phase induction motor of the same kW rating and same winding voltage are compared, then a. Bth will be of same size and efficiency b. The 3-phase induction motor will be

bigger in size and less efficient c. The 3-phase induction motor will be

smaller in size and more efficient d. The 3-phase induction motor will be

bigger in size and more efficient 100. In the slip power recovery method of

speed control of a 3-phase wound rotor induction motor, to operate it in the sub synchronous region of speed, a voltage has to be injected across the rotor terminals a. In phase with the rotor induced emf b. In phase opposition to the rotor

induced emf c. Leading the rotor induced emf by 90° d. Lagging the rotor induced emf by 90°

101.

For the system shown in the above figure, the phase relations of current ‘I’ with respect to the voltage VAB is

a. Zero

b. 90° lead

c. 90° log

d. 180°

102. A-3phase Y/ transformer has per phase turn ration K and line voltage ratio ‘K1’. If the voltage of winding lags the voltage of Y winding by a angle , then K, K1 and are related as

a. 1 30K K and

b. 1 303

KK and

c. 1 3 30K K and

d. 1 3 30K K and

103. Two transformers X and Y with identical ratings and dimensions have 0.8 mm and 1.2 mm thick laminations respectively. If Rm and Xm are the magnetizing branch parameters in the equivalent circuit, then

a. Rm values in both are likely to be equal, but X of Xm is likely to be higher than Xm of Y

b. Xm values in both are likely to be equal, but Rm of X is likely to higher than Rm of Y

c. Xm values in both are likely to be equal, but Rm of X is likely to be lower than Rm of Y

d. Rm values in both are likely to be equal, but Xm of X is likely to be lower than Xm of Y

104. Consider the following statements in respect of important features of IGBT:

1. It has a high impedance gate as that of a MOSFET.

2. It has a low ON State voltage as that of a BIT.

3. It can block negative voltages as in the case of GTO.

Which of these statements are correct?

a. 1 and 2

b. 1 and 2

c. 2 and 3

14 of 15d. 1, 2 and 3

105. Opto couplers are used in transistor base drive circuit for

a. Amplification of base drive signal

b. Isolation between control and power circuits

c. Fast switching of power transistor

d. Protection against over current

106. A single-phase circulating current dual converter is supplying a load, If the triggering angle of one converter is 30°, then the other converter operates at a triggering angle of

a. 30°

b. 60°

c. 90°

d. 150°

107. The purpose of free-wheeling in a thyristor controlled ac to dc converter is to

a. Reduce the current of its associated thyristor to zero so that commutation can take place

b. Share the load current of its associated thyristor

c. Conduct the load current when its associated thyristor is turned off

d. Maintain voltage across load at constant value

108. Consider the following statements

Phase-controlled converters

1. Do not provide smooth variation of output voltage.

2. Inject harmonics into the power system.

3. Draw non-unity power factor (pf) current for finite triggering angle.

Which of these statements are correct?

a. 1, 2 and 3

b. 1 and 2

c. 2 and 2

d. 1 and 3

109. A single-phase thyristorised voltage controller with triggering angle ‘ ’ is supplying an RL load of pf angle ‘ ’. The output voltage can be controlled if

a.

b.

c.

d. ranges form 0° to 180°

110. Assertion (A): In dc to do step down chopper, freewheeling diode is mandatory for RL loads.

Reason (R): A part of energy fed to the RL load is dissipated in the resistance.

a. Both A and Rare true and R is the correct explanation of A

b. Both A and R are true but R is NOT the correct explanation of A

c. A is true but R is false

d. A is false but R is true

111. Assertion (A): In the slip test for determining the daxis and q axis synchronous reactance’s ‘Xd’ and ‘Xq’ respectively of a salient pole machine, the stator has to be fed with suitable reduced voltage at the rated frequency and the rotor (with the field circuit open) has to be rotated at a speed slightly different from the synchronous speed, and the fluctuating terminating voltage and armature current are to be recorded for computing ‘Xd’ and Xq

Reason (R): During the slip test, a slip frequency voltage is indicated across the open field circuit terminals that could be measured by connecting a voltmeter across these terminals.





112. Assertion (A): Phase comparison pilot relaying for the protection of a transmission line is a blocking point.

Reason (R): The pilot signal is not required form the other end to permit tripping.





15 of 15113. Assertion (A): Thyristorised current

source inverters do not operate at high switching frequency.

Reason (R): Thyrised current source inverter is capable of four-quadrant operation.





114. Assertion (A): A piezoelectric crystal is used for measurement of varying force only.

Reason (R): The equivalent circuit of a piezoelectric transducer has a shunt capacitor at its output.





115. Assertion (A): Lag compensation permits a high gain at low frequencies.

Reason (R): Lag compensation is basically a low pass filter.





116. Assertion (A):Stability is major problem in closed loop control systems.

Reason (R): Introduction of feedback affects the location of poles of open-loop system.





117. Assertion (A): The auto increment at auto decrement modes are seldom found in modern processors.

Reason (R): Using two instructions instead of one provides flexibility in implementing a pipeline.





118. Assertion (A): Surface charge density is considered a physical possibility for either dielectrics or perfect conductors.

Reason (R): Surface current density is assumed only in conjunction with perfect conductors.





119. Assertion (A): For continuous communication purposes, satellites are normally placed in geostationary orbit.

Reason (R): In satellite communication, uplink and downlink frequencies are different.





120. Consider an SSB signal where the modulating signal is a speech signal.

Assertion (A): Its envelope detection will not recover the modulating signal.

Reason (R): The envelope of an SSB is constant.





1 of 14

1. The value of electric field at a distance of

1 m from an infinite line charge of density 1 C/m is

a. 0

1

2

b. 02

c. 0 / 2

d. 0 / r

2. In the given figure, if the magnetic flux through the rectangular loop ‘pqrsp’, due to the infinite line current I is ,, the flux linked with double rectangular loop pqtuvwrsp’ will be

a. 3

b. 2

c.

d. Zero 3. An electric dipole (— Q, Q) revolved with

a uniform angular velocity ‘ in a circle about its centre ‘O’. When the dipole is in the position shown in the given figure. the direction of the displacement current density at ‘O’ is

a. ra

b. ra

c. 0a

d. 0a

4. A cubical cavity resonator measures 3 cm on each side. The lowest resonant frequency is nearly a. 6 GHz b. 7 GHz c. 8 GHz d. 9 GHz

5. Electrons in a completely filled band a. Take part in the process of conduction b. Take part in the process of conduction

at low temperature only c. Do not take part in the process of

conduction d. Take part in the process of conduction

at high temperatures only 6. The cooking of the food in a microwave

oven is based on the principle of a. Magnetic hysteretic loss b. Dielectric loss c. Both magnetic hysteretic loss and

dielectric loss d. Evaporation of water

7. Manganese ferrite is a 1 : 1 mixture of a. MnO and CdO b. MnO and Fe2O3 c. MnCl2 and Fe2O3 d. MnCl2 and CdO

8. Match List I with List II and select correct answer: List I A. Diffusion B. Drift C. Free electrons D. Holes List II 1. Conduction band 2. Valence band 3. Fick’s law 4. Electric field

A B C D a. 3 4 2 1 b. 4 3 2 1 c. 3 4 1 2 d. 4 3 1 2

C.S.E Pre-2001


2 of 149. An IC structure is shown in the given

figure. The device that can be realized between terminals labeled (1) and (2) is a

a. Resistor b. Capacitor c. Bipolar transistor d. MOS transistor

10. The contact between aluminum (Al) and moderately doped silicon (Si) will be a. Al – pSi Ohmic and Al — nSi

Schottky b. Al — pSi Ohmic and Al — nSi Ohmic c. Al — pSi Schottky and Al — nSi

Ohmic d. Al pSi Schottky and Al — nSi

Schottky 11. The peak input-voltage to a full-wave

bridge rectifier is 1000 V at 50 Hz. The dc output voltage and ripple respectively are a. 318 V and 50 Hz b. 318 V and 100 Hz c. 636 V and 50 Hz d. 636 V and 100 Hz

12. For a JEET, gm = 1mA/V and Cgs+Cgd+Cgss = 5pF. The symbols have their usual meaning. The ft of the JFET is nearly equal to a. 1 MHz b. 5 MHz c. 30 MHz d. 190MHz

13. A zener diode has a zener resistance of 5 . If the current through the Zener diode changes form 10mA to 20mA, the change of voltage across the zener diode will be a. 0.05 V b. 0.075 V c. 0.1 V d. 0.5 V

14. The CE amplifier is shown in the given figure. The voltage gain of the amplifier is

a. /c ER R

b. /E cR R

c. 1 2 1 2/

c ieR h

R R R R

d. Always <1 15. In the CE configuration of a transistor

amplifier, there is a. No phase change between input and

output voltages b. 180° phase change between input and

output currents c. No phase change between input and

output currents and no phase change between input and output voltages

d. No phase change between input and output currents and 180° phase change between input and output voltages

16. The load current IL in the given circuit is

a. 10 mA

b. 40

3mA

c. 15 mA d. 20 mA

17. An emitter coupled differential amplifier behaves as an excellent double - ended clipper if the magnitude of the input differential voltage exceeds a. 8VT b. 4VT c. 2 VT d. VT

18. The technique of polarization diversity is used

3 of 14a. In satellite communication b. In troposcatter communication c. To combat fading in microwave

communication d. To increase repeater spacing in

microwave link 19. Smiths charts are used to obtain the

impedance relations along a a. Lossless transmission line for different

load conditions b. Lossy transmission line for different

load conditions c. Lossy transmission line terminated at a

load equal to line characteristic impedance

d. Lossless transmi3sion line terminated at a load equal to line characteristic impedance

20. A frequency-modulated voltage wave is given as V = 10 sin 2 5sin 400 t . The

carrier frequency and maximum deviation of the signal are respectively a. 10 MHz and 10 kHz b. 100 MHz and 1 kHz c. 10 MHz and 1 kHz d. 100 MHz and 10 kHz

21. A DSB — SC signal is being detected synchronously. The phase error in the locally generated carrier will a. Cause phase delay b. Cause phase distortion only c. Have the effect of reducing the output

and causing phase distortion also d. Reduce the detected output only

22. Match list I (RM I 051 layer) with list II (Function) and select the correct answer: List I A. Network layer B. Transport layer C. Data link layer D. Presentation layer List II 1. Control of packets 2. Data compression 3. Breaks input bit into frames 4. Breaks data into smaller units

A B C D a. 1 4 3 2 b. 4 1 3 2 c. 1 4 2 3 d. 4 1 2 3

23. For the Hamming block code, if ‘n’ be total word length of the block and ‘k’ be the number of information bits, then an allowable code of this (n, k) family of Hamming code is a. (7, 5) b. (15. 11) c. (31, 25) d. (129, 120)

24. consider the following statements: In comparison to PCM, a DM system suffers from the disadvantages of 1. Slope overload distortion. 2. Larger bandwidth 3. more complex circuitry 4. Inferior performance Which of these statements is/are correct? a. 1 alone b. 1 and 2 c. 2 and 3 d. 4 alone

25. If the distance ‘d’ between the radar nad the target is reduced to ‘d/2’ then the reviewed the received power becomes ‘N’ times the power received earlier. The value of ‘N’ is a. 2

b. 8 c. 4 d. 16

26. In a TV receiver, if the picture is rolling, this may be due to a. Problem in vertical synchronization b. Problem in horizontal Synchronization c. No vertical deflection d. No horizontal deflection

27. The circuit with inputs A and B shown in the given figure performs the

a. AND operation b. Or operation c. NAND operation d. NOR operation

4 of 1428. For the product-of-sums expression

L X Y X Z the equivalent sum

of-products expression will be

a. XY X Z

b. XY XY

c. XY X Z

d. XY XZ 29. If the input to a 5 bit ladder type DAC is

11101 (where ‘0’ and ‘1’ represents 0 V and 10 V respectively), the output voltage will be approximately a. 1 V b. +9 V c. -9 V d. +10 V

30. Static RAM is preferred over dynamic RAM when the requirement is of a. Slow speed of operation b. Larger storage capacity c. Lower access time d. Lower power consumption

31. Four memory chips of 16 × 4 size have their address buses connected together. The resulting memory system will be of size a. 64×4 b. 16×16 c. 32×8 d. 256×1

32. In which one of the following modes of operation, shift register ceases to work as a shift register? a. SISO b. SIPO c. P150 d. PIPO

33. Consider the following expression:

1. , , , 1, 2, 4,7,8,11,13,14Y f A B C D

2. , , , 3,5,10,11,12,13,14Y f A B C D

3. , , , 0,3,5,6,9,10,12,15Y f A B C D

4. , , , 0,1,2, 4,6,8,9,15Y f A B C D Which of these expression are equivalent to the expression, Y A B C D ?

a. 2 and 3 b. 1 and 4

c. 2 and 4 d. 1 and 3

34. Which one of the following difference equations will satisfy the JK flip-flop truth table?

a. 1n n n n nQ J Q K Q

b. 1n n n n nQ J Q K Q

c. 1n n n n nQ J Q K Q

d. 1n n n n nQ J Q K Q

35. An overflow occurs in integer binary arithmetic when a. A carry comes form the most

significant bit b. The sign of the first operand is

different form the sign of the result c. Exclusive NOR of carry from the most

significant but and carry form the next most significant but is ‘1’

36. The advantages of immediate addressing is a. To decode the operand easily b. To execute the instruction immediately c. Not to fetch operand from memory d. To allow both positive and negative

operands 37. To construct a 210 input multiplexer, the

requited number of 2 input multiplexers is a. 31 b. 63 c. 127 d. 1023

38. The 4 bit ripple counter which is composed of flip-flops with a propagation delay of 20 ns, would have the maximum counting speed of a. 1MHz b. 4MHz c. 10 MHz d. 100 MHz

39. The cache memory has a high-speed of 4Onsandahit ratio of 80%. The regular memory has an access time of 100 ns. The average effective time for CPU to access memory is equal to a. 52ns b. 6Ons c. 70 ns d. 80 ns

40. Match List I (Power Electronic Devices) with List II (Symbols) and select the correct answer:

5 of 14List I A. GTO thyristor B. Triac C. IGBT D. BJT List II

A B C D a. 1 2 3 4 b. 1 2 4 3 c. 2 1 3 4 d. 2 1 4 3

41. Natural commutation of a thyristor takes place when a. Anode current becomes zero b. Gate current becomes zero c. Voltage across the device becomes

zero d. Voltage across the device becomes

negative 42. A gate-turn-off (GTO) thyristor

a. Requires a special turn-off circuit like a thyristor

b. Can be turned off by removing the gate pulse

c. Can be turned off by a negative current pulse at the gate

d. Can be turned off by a positive current pulse at the gate

43. The SCR circuit is shown in the given figure. Which one of the following wave forms represent ‘VT’ when input voltage v is sinusoidal?

44. For a step-down chopper, V1 is the source

voltage, ‘R’ is the load resistance and is the duty cycle. RMS and average values of thyristor currents for this chopper are, respectively

a. s sV Vand

R R

b. s sV Vand

R R

c. s sV Vand

R R

d. s sV Vand

R R

45. A step - up chopper is required to deliver a load voltage of 660 V from 220 V dc source. If the non -conduction time of SCR is 100 is, the required pulse-width will be a. 300 s

b. 250 s

c. 200 s

d. 150 s

46. In a 3-phase half-wave diode rectifier, the ratio of average output voltage to per-phase maximum ac voltage is a. 0.955 b. 0.827 c. 1.654 d. 1.169

47. Figure 1 shows a 3-phase invertors fed by a constant voltage source VDC and connected to a balanced resistive load at the output. Each switching device may conduct for 1200° or for 180°. The wave form shown in the Figure Ills the

6 of 14

a. Line voltage with 120° firing b. Load phase voltage with 120° firing c. Line voltage with 180° firing d. Load phase voltage with 180° firing

48. The given figure shows electric power input Pe to a a lossless synchronous motor as a function of torque angle . The load is suddenly increased form P0 to Ps and the motor oscillates around s between 0 and m.

Consider the following statements derived from the figure regarding the relationship between the motor speed and its synchronous speed s at different points in the oscillating cycle: (i) At point 1, = s (ii) At point 2, while oscillating from 1

towards 3, < s (iii)At point 2, while oscillating from 3

towards 1, > s Which of these statements (s) is/are correct? a. ii and iv b. i,ii and iv c. i and iii d. Iii alone

49. The reactance of a generator designated X” is given as 0.25 Pu based on the generator’s name plate rating of 18 kV, 500 MVA. If the base for calculations is changed to 20 kV, 100 MVA, the generator reactance X on new base will be a. 1.025 Pu b. 0.05 Pu c. 0.0405 pu d. 025 pu

50. Consider the following statements:

The calculations performed using short - line approximate model instead of nominal it model for a medium length transmission line delivering lagging load at a given receiving - end voltage always result in higher 1. Sending - end current 2. Sending - end power 3. Regulation 4. Efficiency Which of these statements are correct? a. 1 and 2 b. 3 and 4 c. 1, 2 and 3 d. 1, 2 and 4

51. The severity of line to ground and three-phase faults at the terminals of an unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu, Z1 = Z2 = j 0.1 Pu and Z0 = j 0.05 pu for the alternator, then the required inductive reactance for neutral grounding is a. 0.0166 pu b. 0.05 pu c. 0.1 pu d. 0.15 pu

52. The surge impedance loading of a long transmission line can be increased without adversely affecting its stability by connecting a. Lumped inductances in series with the

line b. Lumped inductances in shunt with the

line c. Lumped capacitances in shunt with the

line d. Lumped capacitances in series with the

line 53. A transmission line has equal voltages at

the two ends, maintained constant by two sources. A third source is to be provided to maintain constant voltage (equal to the end voltages) at either the mid-point of the line (case 1) or at 75% of the distance from the sending end (case 2). Then the maximum power-transfer capabilities of the line in the original case, case 1 and case 2 respectively, will be in the ratio of a. 1:1:1 b. 1:2:1/0.75 c. 1:2:4 d. 1:4:16

7 of 1454. A short length of cable is connected

between dead-end tower and sub-station at the end of a transmission line. Which of the following will decrease, when voltage wave is entering from overhead line to cable? 1. Velocity of propagation of voltage

wave. 2. Steepness of voltage wave. 3. Magnitude of voltage wave. Select the correct answer using the codes given below a. 1 and 2 b. 2 and 3 c. 3 and 1 d. 1, 2 and 3

55. The corona contributes a rd harmonic to the charging current of the line, because it a. Occurs every half cycle of the

fundamental frequency b. Induces a 3rd harmonic voltage

between line and earth c. Produces random harmonics, but only

3rd harmonic is passed through the line capacitance

d. Affects the system grounding for which a 3rd harmonic voltage appears on the line, and causes 3rd harmonic charging current

56. A single line diagram of a power system is shown in the given figure. The diagonal elements of the YBUS matrix is

a. j 0.7 pu, j 0.75 pu, j 0.45 Pu b. – j 0.7 pu, – j 0.75 p – j 0.45 pu c. – j 7.0 pu, – j 6.0 pu, – j 9.0 Pu d. j 7.0 pu, — j 6.0 pu, j 9.0 pu

57. In load - flow analysis, the load at a bus is represented as a. A constant current drawn from the bus b. A constant impedance connected at the

bus c. Constant real and reactive powers

drawn from the bus d. A voltage - dependent impedance at

the bus

58. Match List I (Relay) with List II (Equipment) and select the correct answer: List I A. Mho Relay B. Negative Sequence Relay C. Thermal Relay. List II 1. Bus bar 2. Motor 3. Generator 4. Transmission line

A B C a. 1 3 2 b. 2 4 1 c. 4 2 3 d. 4 3 2

59. Shunt resistor is connected across the contacts of a circuit-breaker in order to a. Damp out the restricting transient b. Bypass the arc current c. Limit the short-circuit current d. Reduce the damage to the contacts due

to arcing 60. Phase comparison relaying is

a. Used for providing back-up protection to transmission lines

b. Immune to the effects of power surges c. Adversely affected by the currents

flowing in the protected line due to mutual induction from another nearby circuit

d. Adversely affected by the loss of synchronism between sources of generation beyond the ends of the protected line

61. Maloperation of differential protection of transformers due to magnetizing inrush current is prevented by a. Setting the current of the relay higher

than the maximum value of inrush current

b. Keeping the time-setting long enough for the inrush current to fall to a value below the primary operating current of the relay

c. Bypassing the inrush current from the operating coil of the relay

d. Filtering the third harmonic content of the inrush current flowing through the operating coil and passing through the restraining coil

8 of 1462. Incremental fuel costs in Rs / MWh for a

plant consisting pf two units are given by dF1 / dP1 = 0.4P1+400 and dF2/dP2=0.48 P2+320. The allocation of loads P1 and P2 between the units 1 and 2, respectively, for minimum cost of generation for a total load of 900 MW is a. 200 MW and 700 MW b. 300 MW and 600 MW c. 400 MW and 500 MW d. 500 MW and 400 MW

63. Given figure shows an electromagnet to lift a load of W gram. Assume infinite permeability for iron. The ampere turns of the exciting coil to maintain an equilibrium at an air-gap of x mm would be given by

a. 0.874Wx

A

b. 0.282Wx

A

c. 8.74Wx

A

d. 2.82Wx

A

64. The series winding of a cumulatively compounded dc motor is short -circuited while driving a load at rated torque. This results in a. Reduction in both the armature current

and the motor speed b. Increase in the armature current and

reduction in the motor speed c. Increase in- both the armature current

as well as the motor speed d. Reduction in the armature current and

increase in the motor speed 65. Consider the following statements

regarding an electrical machine having cylindrical stator and salient-pole rotor:

1. Reluctance torque is produced when rotor winding is excited.

2. Reluctance torque is produced when stator winding is excited.

3. When both stator and rotor windings are excited, electromagnetic torque is produced.

4. When both stator and rotor windings are excited, electromagnetic as well as reluctance torques are produced.

Which of these statements are correct? a. 2 and 4 b. 1 and 4 c. 1 and 3 d. 2 and 3

66. The identical synchronous machines A and B, running at the same speed, are linked through inductors as shown in the given figure:

Machine A will supply active and reactive power to machine B when is a. Positive and VA is less than VB b. Positive and VA is greater than VB c. Negative and VA is less than VB d. Negative and VA is greater than VB

67. The given figure shows the equivalent circuit of a 3-phase induction motor with deep-bar rotor. The sequence of the magnitudes of the parameters of resistances and reactance’s in the ascending order is

a. / ' / ' ', ,s r r r c mR R X X R X

b. / ' / ' ' 's r s m cX X R X R

c. ' ' / ' / ' 'r s s r c mR R X X R X

d. ' ' / ' / ' 's r s r m cR R X X X R

68. Which one of the following statements for a dc machine which is provided with inter pole windings (IW) as well as compensating winding (CW) is correct?

9 of 14a. Both IW and CW are connected in

series with the armoire winding, b. Both IW and CW are connected in

parallel with the armature winding c. IW is connected in series but CW is

connected in parallel with the armature winding

d. IW is connected in parallel but CW is connected in series with the armature winding

69. A 3-phase 20-pole, synchronous generator has 180 stator slots with single-layer full pitch coils. There are 6 conductors per slot and all coils per phase are connected in series. The rotor is driven at 300 rpm and the flux per pole (sinusoid ally distributed) is 25 mWb. The voltage induced per phase is nearest to a. 500 V b. 1000 V c. 1500 V d. 2000 V

70. The Zero Power Factor Characteristic (ZPFC), along with the Open - Circuit Characteristic (0CC) as shown in the given figure are used to determine the Leakage Reactance Drop IaXI at the rated current Ia from the “Potier Triangle” ABC. In this triangle, BC represents the Isxi (=Vx) drop, because

a. Vx is induced by the mmf AB b. VX is induced by the mmf BD c. VX is induced by the mmf OF d. VX and the air-gap voltage Er are 180°

out of phase at zero p.f. load 71. To calculate the full - load voltage

regulation of a synchronous generator at any power factor using mmf method, it is required to have a. Open-circuit and short - circuit

characteristics b. Open - circuit and zero power factor

characteristics

c. Open - circuit characteristics, field current at rated short- circuit current and armature resistance

d. Short - circuit characteristics, zero power factor characteristics and armature resistance

72. Match List I with List II and select the correct answer: List I (Motors) A. 1 -phase induction motor B. Steppe motor C. Universal motor D. Brushless dc motor List II (Applications) 1. Fast- acting servo drive 2. Hand drilling machine 3. Computer numerical control 4. Domestic pump

A B C D a. 3 4 1 2 b. 3 4 2 1 c. 4 3 1 2 d. 4 3 2 1

73. In a 3-phase induction motor, the rotor impedance angle at standstill is . The load angle will be a. b. c. / 2 d. / 2

74. In the slew range of a stepper motor, it a. Can start, stop and reverse as desired b. Cannot start but can stop and reverse

on command c. Cannot start, stop and reverse on

command d. Cannot start and synchronize but can

reverse on command 75. A 3-phase induction motor develops a

torque T when driven from a balanced 3-phase supply. The terminal voltage and frequency are halved so that the air-gap flux remains the same while the load torque is kept constant. Then the slip a. Is reduced to half b. Remains same as the previous value c. Speed is reduced to half d. Speed remains the same

76. Consider the following statements: A ceiling fan fails to start because 1. Main winding is open-circuited.

10 of 142. Auxiliary winding is open-circuited. 3. Capacitor is short-circuited. 4. Supply terminals are reversed. 5. Main and auxiliary winding

connections are interchanged. Which of these statements are correct? a. 1, 2 and 5 b. 2, 3, 4 and 5 c. 1, 2 and 3 d. 1, 3 and 4

77. Hysteretic loss of a transformer designed at voltage ‘V’ and frequency ‘f’ is Ph. If the transformer is operated from a voltage xV’ and frequency ‘xf’ the hysteretic loss for a Steinmetz constant of 2 will be a. X2Ph b. XPh c. Ph d. X3Ph

78. Which one of the following figures represents the correct direction of flow of currents in the different sections of the windings of an auto transformer?

79. Assertion (A): The driving point

admittance function of a passive network cannot have multiple poles on the j - axis. Reason (R) : Multiple poles on the j - axis give rise to time domain functions of the type t cos t and t sin t. a. Both A and R are true and R is the

correct explanation of A b. Both A and R are true but R is NOT

the correct explanation of A c. A is true but R is false d. A is false but R is true

80. Assertion (A): If the voltages across R. L and C elements connected in series in an ac circuit are 300 V, 100 V and 500 V respectively, then the total voltage applied will be 500 V. Reason (R): The applied voltage in LCR series circuit is equal to the maximum

voltage existing across any of these elements. a. Both A and R are true and R is the



81. Assertion (A): Hardware stack registers speed up the operation of computer.. Reason (R): Hardware stack registers reduce the number of memory references required. a. Both A and R are true and R is the



82. Assertion (A): ECL gate has less propagation delay as compared to TTL and CMOS gates. Reason (R): ECL gate consumes less power. a. Both A and R are true and R is the



83. Assertion (A): The individual active and passive components in IC should be electrically isolated from one another before metallization. Reason (R): The epitomical layer in which these components are fabricated can provide a common leakage path. a. Both A and R are true and R is the



84. Assertion (A): A low voltage standing wave ratio (VSWR) is the goal in a transmission line. Reason (R): The higher the VSWR the greater is the mismatch on the line. a. Both A and R are true and R is the


the correct explanation of A

11 of 14c. A is true but R is false d. A is false but R is true

85. Assertion (A): Square law detectors, though simple, are not satisfactory for the detection of amplitude modulated signals. Reason (R): Square law detection leads to large second harmonic distortion, which is proportional to the modulation index of the sinusoidal signal. a. Both A and R are true and R is the



86. For network shown in the given figure, the current in the 2 resistor would be

a. 5 A b. 20A c. 25A d. 30A

87. In the given circuit, if the inductor is initially relaxed, then the current in the circuit will be

a. Zero

b. /L R t

c. 1 Rt

eL L

d. 1

1Rt

eL L

88. In a two-port network, the output short-circuit current was measured while the source voltage at the input was 1 V; the value of the output current would provide the parameter a. B b. y12

c. y21 d. h21

89. An RC driving point impedance function has zeros at s = – 2 and s = – 5. The admissible poles for the function are a. S = 0 and s= –6 b. S = – l and s = –3 c. S = 0 and s –1 d. S = –3 and s = –4

90. For the circuit shown in the given figure, the switch ‘K’ was closed for a long time till steady state conditions reached. At time t = 0, the switch ‘K’ is opened, then the current through inductor will be

a. 5 cos 10t b. 5 cos 100t c. 5 cos 1000t d. 5 cos 10000t

91. For the circuit shown in the given figure, steady state is reached with switch ‘S open. At t = 0, when switch S is closed, then the values of v (in V) and dv/dt (in V/s) respectively at t = 0+ will be

a. 1 and 0 b. 2 and 1 c. 2 and 0 d. 1 and 1

92. Input impedance of a CR0 measured at 10 kHz is Z1 and at 10 MHz is Z2. Which one of the following relations is correct? a. 1 2| | | |Z Z

b. 1 2| | | |Z Z

c. 1 2| | | |Z Z

d. 1 2| | 1000 | |Z Z

93. The quality factor of a series circuit consisting of 20 resistance, 0.05 H inductance and 1 F capacitance is

12 of 14a. 20.15 b. 11.2 c. 8.7 d. 4.5

94. The voltage v0 for the circuit shown in the given figure will be

a. 1

1s

MV

L

b. 1

1s

MV

L

c. 1

1s

MV

L

d. 2

1s

MV

L

95. The dc component of the function it sin t is a. 0 b. 1 c. 2 d. 2 /

96. Consider the following statements: If the differential equation for the circuit shown in the given figure is v(t) = – 4 v(t) + 4. Then the set of values of E, R and C are, respectively

1. 1V,1 and 0.25 F 2. 2V.0.5 and 0.5F 3. 2 V. 1 and 0.5 F. 4. 1 V.0.25 and 1 F. Which of these statements are correct? a. 1 and 2 b. 2 and 3 c. 3 and 4 d. 1 and 4

97. If X(z) = Z transform of x(n), then a. 1 0X x

b. 1X x n

c. 1 0X x

d. 1X x n

98. The function x(t) is shown in the given figure. If X j is the fourier transform

of the x(t), then | |X j at = 0 will be

a. 0.5 b. 1.5 c. 2 d. 3

99. The function 2n is equal to

a. n

b. 1/ 2 n

c. 2 n

d. 2 / 2n

100. A band pass signal having the frequency contents in the range of 1 MHz to 2 MHz is to be sampled. The original signal can be reconstructed, if the minimum sampling rate is a. 106 samples/s b. 2 ×106 samples/s c. 4 × 106 samples/s d. 6 × 106 samples/s

101. For the feedback system shown in the given figure, the forward path does not affect the system output when KG is

a. Small b. Negative c. One d. Very large

102. If a system has an open loop transfer

function 1

1

s

s

then the gain of the system

at frequency at 1 rad/s will be a. 1 b. ½ c. Zero

13 of 14d. -1

103. A system block diagram is shown in the given figure. The overall transfer function of the system is

The value of ‘X’ would b e equal

a. H3 b. G1H3 c. G2H3 d. G3H3

104. The signal flow graph of the system is shown in the given figure. The transfer function C(s) / D(s) of the system is

a.

1 2

1 21

G s G s

G s G s H s

b.

1 2

1 21

G s G s

G s G s H s

c.

2

1 21

G s

G s G s H s

d.

2

1 21

G s

G s G s H s

105. The response of a system to a unit ramp input is ½ t-1/8 u(t)+1/8e-4t. Which one of the following is the unit impulse response of the system?

a. 41 te

b. 42 1 te

c. 4te

d. 42 te 106. If a second order system has poles at —1 ±

j, then step response of the system will exhibit a peak value at a. 4.5 s b. 3.5 s

c. 3.14 s d. 1 s

107. The gain margin of a unity negative feedback system having forward transfer

function 1

k

s sT is

a. Infinity b. kT c. 1 d. Zero

108. The impulse response of a linear system is given by g(t) =Ke-t/r A tangent is drawn to the impulse response curve at time t=0. the tangent will intersect the time axis at a. 1/ 2 b. c. 2 d. K

109. A system is shown in the given figure. The value of K which gives a steady - state error of 20% to a unit step - input is given by

a. 500 b. 100 c. 20

d. 4

110. The transfer function for a system is

2, 0

1 3 4

K sG s K

s s s

Two branches (loci) of the plot directed along asymptotes are centered at a point

a. –3

b. –4

c. –2

d. –1

111. The number of roots in the left-half of s-plane for the equation s3 — 4s2 + s + 6 = 0, would be

a. 1

b. 2

c. 3

d. 4

112. Consider the following features:

14 of 141. Squirrel-cage or drag-up type rotor.

2. Nearly linear torque -speed characteristics.

3. High X / R ratio.

Which of these features are possessed by a two-phase ac servomotor?

a. 1,2 and 3

b. 1 and 2

c. 2 and 3

d. 1 and 3

113. The current ‘I’ flowing through a resistance of value 100 0.2% is 4 0.5%A

The uncertainty in measurement of power is

a. 1600 W ± 0.01%

b. 1600 W ± 0.02%

c. 1600 W ± 0.05%

d. 1600 W ± 1.2%

114. The impedances of a basic ac bridge arms are

250

100 60

400 30

AB

BC

CD

Z

A

Z

DAZ Unknown

If 1000 radian/s, the components of the unknown arm has the resistance

500 3 in

a. Series with a capacitor of 2. F

b. Parallel with a capacitor of 2 F

c. Series with an inductor of 2 H

d. Parallel with an inductor of 2 . H

115. In a low power-factor wattmeter. compensating coil is employed in order to

a. Neutralize the capacitance effect of pressure coil

b. Compensate for the inductance of pressure coil

c. Compensate for the error caused by power loss in the pressure coil

d. Reduce the error caused by the eddy - currents

116. The battery voltage of an analog multimetr drops by 20% of its original value. The

multimeter is used to measure dc voltage in a circuit. The true voltage compared to the measured value is

a. 10% higher

b. 20% higher

c. 20% lower

d. Same

117. Which one of the following causes the disc in an induction type of energy meter to rotate in the opposite direction?

a. The breaking magnet is faulty

b. Both current coil and voltage coil are wrongly connected

c. Either current coil or voltage coil is wrongly connected

d. The load is highly reactive

118. In a semiconductor strain gauge, the change in resistance on application of strain is mainly due to the change in its

a. Length

b. Diameter

c. Resistively

d. Length and diameter

119. In a digital voltmeter, the oscillator frequency is 400 kHz and the ramp voltage falls from 8 V to 0 V in 20 ms. The number of pulses counted by the counter would be

a. 4000

b. 8000

c. 16000

d. 32000

120. The following units are used in a data-acquisition system

1. Central Processing Unit

2. Memory

3. Transducer

4. ADC

The sequence of placement of these units from input to output is

a. 4, 3, 1, 2

b. 3, 4, 1, 2

c. 3, 4, 2, 1

d. 4, 3, 2, 1

1 of 13

1. Match List I (Powers system components)

with List II (Relaying schemes) and select the correct answer: List I A. Power Transformer B. Transmission Lines C. Alternator List II 1. Differential relaying 2. Distance relaying

A B C a. 1 1 2 b. 2 1 1 c. 1 2 1 d. 2 1 2

2. Match List I (Feature) with List II (Device) and select the correct answer: List I A. Low on-state resistance B. High input impedance C. Improved di /dt behavior D. Good turn-off gain List II 1. Thyristor 2. BJT 3. MOSFET 4. Triac 5. Amplifying gate thyristor

A B C D a. 5 3 4 1 b. 2 1 5 3 c. 5 1 4 3 d. 2 3 5 1

3. A d.c. chopper is operating at a frequency of 2 kHz from a 96 V d.c. source to supply a load resistance of 8 . The load time constant is 6 ms. If the average load voltage is 57.6 V, on time Ton of the chopper is a. 30ms b. 3ms c. 0.3 ms d. 0.3 s

4. Consider the following statements: Overlapping communication in a phase controlled a.c. to d.c. converter 1. Increase the reverse bias duration of a

thyristor 2. Reduces the displacement factor

3. Saves the reactive power 4. Is responsible for voltage regulation on

the d.c. side of the converter Which of these statements are correct?

a. 1, 2 and 3 b. 2, 3 and 4 c. 1, 3 and 4 d. 1, 2 and 4

5. The converter transformer interposed between the a.c. source and midpoint (star point) converters have special construction a. Because the load currents are non-

sinusoidal b. In order to improve the converter

performance c. In order to strengthen them d. In order to avoid d.c. magnetization of

the core 6. A single phase a.c. voltage controller feeds

a pure resistive load. At a firing angle a, thyristor conducts for an angle . If the load is replaced by a pure inductance keeping the firing angle constant, the conduction angle of the thyristor would be a. 2 b. c. /2 d. /3

7. The feedback diodes in a d.c. to a.c. thyristor inverter a. Freewheel the load current b. Provide reverse bias effectively to the

thyristors for turnoff c. Improve the switching properties of the

inverter d. Improve the harmonic distortion of the

inverter output current 8. Match List I (Fabrication process step)

with list II (Associated problem) and select the correct answer: List I A. CMOS fabrication B. IOM implantation C. LOCOS D. Electron beam lithography List II 1. Bird’s beak 2. Channeling 3. Latch-up

C.S.E Pre-2002


2 of 134. Proximity effect

A B C D a. 3 4 1 2 b. 1 2 3 4 c. 3 2 1 4 d. 1 4 3 2

9. The purpose of providing n + buried layer in a bipolar junction transistor fabrication process is to 1. Reduce collector resistance 2. Reduce base resistance 3. Provide isolation between adjacent

transistors Which of these statements is/are correct? a. 1, 2 and 3 b. 1 and 2 c. 1 only d. 3 only

10. Assertion (A): Two wires of same length with different cross-sectional areas are connected in series. The heat produced by the current is more in the thicker wire. Reason (R): The thicker wire has low resistance. a. Both A and R are true and R is the



11. Assertion (A): The continuous time differentiator is an unstable system in the bounded-input. bounded-output (BIBO) sense. Reason (R): The bounded input x(t) sin t2 would result in an unbounded output. a. Both A and R are true and R is the



12. Assertion (A): Introducing negative feedback in an amplifier results in a reduced bandwidth. Reason (R): The gain bandwidth product of an amplifier is a constant. a. Both A and R are true and R is the



13. Assertion (A): When one tries to control the majority carrier concentration in an extrinsic semiconductor, its minority carrier concentration automatically gets changed. Reason (R): Einstein relation holds good in case of doped semiconductor. a. Both A and R are true and R is the



14. Assertion (A): Negative feedback in amplifiers improves performance. Reason (R): Gain of the amplifier is reduced by use of negative feedback. a. Both A and R are true and R is the



15. Assertion (A) : ECL is a very high speed logic gate. Reason (R): Bipolar transistors are used to realize ECL gates. a. Both A and R are true and R is the



16. Assertion (A): Any I3oolean function can be realized by using a suitable multiplexer. Reason (R): A multiplexer can be realized using NAND and NOR gates, which are universal gates. a. Both A and R are true and R is the



17. Assertion (A): Indexed addressing mode is never used in a computer. Reason (R): The address of the operand is

obtained by adding the base address and the index in the indexed addressing mode. a. Both A and R are true and R is the


the correct explanation of A c. A is true but R is false

3 of 13d. A is false but R is true

18. Assertion (A): Fiquently used subroutines are called by the RST instruction. Reason (R): RST instruction is a single byte instruction whereas the regular CALL instruction is a 3 byte instruction. a. Both A and R are true and R is the



19. Assertion (A): Laboratory Cathode Ray Oscilloscopes employ electrostatic deflection system. Reason (R): Electrostatic deflection systems are most suitable for small screens. a. Both A and R are true and R is the



20.

Referring to the circuit shown above the current in 18 resistors is a. 2A b. 1.5A c. 1A d. 0.5 A

21.

An ideal ammeter is connected between terminals A and B of the network shown above. The current through the ammeter is a. 0.8 A b. 1.6 A c. 0A d. 3.2A

22. A unit step voltage is connected across aeries circuit consisting of a 1 H Inductor

and a 2 resistor at time = 0. The initial current in the inductor is zero. Match List I (Parameter) with List II (Value) and select the correct answer:

List I A. The initial current through the circuit B. The steady-state value of current

through the circuit C. The value of the current through the

circuit at time = 1/2 s D. The initial slope of the current List II 1. 1/2A 2. 2A 3. zero

4. 11 e

5. 11/ 2 1 e

6. 0A/s A B C D

a. 3 2 5 6 b. 4 1 7 5 c. 3 1 5 6 d. 4 2 7 5

23. Consider the following statements with reference to RC impedance function 1. All poles and zeros of the function are

located on the positive real axis 2. Poles and zeros are interlaced 3. The lowest critical frequency is a zero 4. The lowest critical frequency is a pole The properties of RC impedance function are a. 1 and 2 b. 2 and 3 c. 2 and 4 d. 1 and 4

24.

For the circuit shown above the total

impedance is a. 7 0j

b. 5 0j

c. 0 8j

d. 7 0j

25.

4 of 13

For the circuit shown above, the initial inductor current is 2 A. The value of i(t) for t > 0 is a. 0.5 – 0.5 e-t b. 1– e-t c. 0.5 – 0.25 e-t d. 0.5 + 0.5 e-t

26. A star-connected pure resistive load and a delta-connected pure indicative load are connected in parallel to a 2 phase,

1000 3V stare-connected source. Each arm of the resistive load is 100 and each arm of the inductive load is 300 . The total line current supplied by the source is

a. 10 2A b. 20A

c. 10 6A

d. 20 / 3A 27. A function f(.) is linear under the

condition(s) a. 1 2 1 2f X X f X f X only

b. f kx kf x only

c. 1 2 1 2f x x f x f x and

f kx kf x

d. 1 2 1 2f x x f x f x or

f kx kf x

28. Match List I (Signals) with List 11 (Laplace Transformers) and select the correct answer: List I A. te u t

B. 21/ s C. u t

D. tte u t

List II 1. 21/ s

2. 2

1

1s

3. 1/s

4. 1

1s

U(t) denotes the unit step function.

A B C D a. 4 1 3 2 b. 2 3 1 4 c. 4 3 1 2 d. 2 1 3 4

29. Consider a system described by the

transformer function 2

2 3

2 5

sG s

s s

It is subjected to an input f(t) 10 u(t). The initial and final values of the response are given by a. 0, 2/3 b. 1, 4 c. 0,6 d. 0,4

30. The impulse response of a linear time invariant system is given by h(t) 2 e-t u(t). The unit step response is given by

a. 2 1 tY t e u t

b. 2 1tY t e u t

c. 22 1 tY t e u t

d. 22 2 tY t e u t

31. The v - i characteristic of a resistor is 22i V The resistor is

a. Linear, passive, bilateral b. Non-linear, passive, bilateral c. Non-linear, active, bilateral d. Non-linear, active, unilateral

32. The unit impulse response of the system described by y(n) –y(n –1) = x(n) –x(n –1) is a. (n) b. U(n) c. 1 d. Zero

33. The sequences u[n] and u [–n –1] a. Are both non-causal sequences b. Have the same z -transforms with the

same regions of convergence c. Have the same z-transforms with

different regions of convergence d. Do not have a z-transform at all

34. A unity feedback system has open loop T.

F. 16

1.6G s

s s

. The natural

frequency of the system is a. 16 b. 8 c. 2 d. 4

35. Loop gain vs. phase plot is known as

5 of 13a. Nyquist plot b. Bode plot c. Nichol’s chart d. Inverse Nyquist plot

36. A closed -loop system is stable when all its poles in the s - plane lie a. On the positive real axis b. On the imaginary axis c. In the left half d. In the right half

37. The transfer function 1 0.5

1

s

s

represents a

a. Lead network b. Lag network c. Lag -lead network d. PID controller

38. A. C. Servomotor is a a. 3-phase induction motor b. 2- phase induction motor c. 1 - phase induction motor d. 2-phase synchronous motor

39. Amplifying is a type of a. Magnetic amplifier b. Rotating amplifier c. Electronic amplifier d. Synchro transformer

40. sampled signal has z-transform

2

1

TzR z

z

Which of the following

time-domain signals does it represent? a. Exponential b. Step c. Ramp d. Sinusoidal

41. A circular disc of radius R carries a uniform surface charge density. When it revolves at a uniform angular velocity about its centre and in its own plane, the magnetic flux density at the centre of the disc is B. If the radius of the disc is doubled and the original charge spread out uniformly on the extended area, the magnetic field at the centre would be a. B/4 b. 13/2 c. 13 d. 213

42. Consider the following statements with regard to force per unit length between two stationary, long parallel filamentary currents

1. It is directly proportional to the product of the magnitudes of the currents

2. It satisfies Newton’s third law 3. It is attracting if the currents are in the

same direction Which of these statements are correct? a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2 and 3

43. An isotropic antenna is radiating 3 kW. The field at 3 km distance is a. 0.1 V/m b. 10 V/m c. 0.01 V/m d. 0.2 V/m

44. A cubical cavity of dimension 2.36 cm is resonating in TE101 mode. The resonant frequency for the mode is a. 10 GHz b. 9 GHz c. 8.5 GHz d. 12 GHz

45. If the cut-off frequency of a parallel plate wave guide for TE10 mode is 2000 MHz, the cut-off frequency for TE20 mode will be a. 1000 MHz b. 2000 MHz c. 3000 MHz d. 4000 MHz

46. A lossless line length / 4 and characteristic impedance Z0 transforms a resistive load R into an impedance

20 /Z R .

When the line if / 2 long, the transformed impedance will be

a. 20 /Z R

b. 202 /Z R

c. Z0 d. R

47. The divergence of a vector 2 2 36A ix j y kz at point P in space

whose coordinates are (2,4,1) is a. 55 b. 65 c. 50 d. 40

48. Consider the following statements in respect of energy bands in a solid:

6 of 131. Energy bands at high energy have

more width than those bands at low energy

2. Low energy bands correspond to valence electrons

3. There are always some energy bands that are not filled

Which of these statements is/are correct? a. 1, 2 and 3 b. 1 and 2 c. only 2 d. 1 and 3

49. Match List I (Name) with List II (Fabrication/Property) and select the correct answer: List I A. Intrinsic semiconductor B. p-type semiconductor C. n-type semiconductor D. Extrinsic semiconductor List II 1. Acceptor type of impurity is added to

semiconductor 2. Donor type of impurity is added to

semiconductor 3. Doped semiconductors 4. Electrical property is same as that of

pure semiconductor A B C D

a. 4 3 2 1 b. 2 1 4 3 c. 2 3 4 1 d. 4 1 2 3

50. Two magnetic materials, A and B, have their electrical conductivities in the ratio 4 : 9. Eddy current losses in the materials A and B are in the ratio a. 2:3 b. 3:2 c. 9:4 d. 4:9

51. In a junction diode, the ratio of the junction resistance under reverse bias to that under forward bias has a typical value a. 10-3 b. 1 c. 103 d. 106

52. When the mobile phone is put ‘on the air, the first information that reaches Mobile Telephone Switching Office (MTSO) is the a. Caller’s telephone number

b. Serial number of the mobile phone assigned by the manufacturer

c. Personal code used by the caller to unlock the telephone

d. Called telephone number 53. Match List I (Link Technology) with List

II (Usable bandwidth) and select the correct answer: List I A. Co-axial cable B. Twisted pair C. Terrestrial microwaves D. Satellite microwaves List II 1. 2 Mbps 2. 1 6bps 3. 2.4 6bps 4. 4.6 6bps

A B C D a. 2 1 3 4 b. 4 3 1 2 c. 2 3 1 4 d. 4 1 3 2

54. ‘BAD is the hexadecimal representation of a binary number. If the number represents only the magnitude, its decimal equivalent is a. 2749 b. 2989 c. 1213 d. 111013

55. The addressing mode in which the machine language instruction itself includes the data is called a. Immediate b. Indexed c. Indirect d. Direct

56. Which one among the following I/O methods wastes a lot of CPU time by putting it into many wait states? a. Hand shaking b. Intermitting c. Synchronous serial d. Asynchronous serial

57. Consider the following statements: When compared with micro programmed control, the following are the advantages of hardwired control 1. It consumes less power 2. It generates the control signals faster 3. It is more reliable Which of these statements are correct? a. 1, 2 and 3

7 of 13b. 1 and 2 c. 2 and 3 d. 1 and 3

58. On a certain memory chip is written 4 k ×8; it implies that it has data input lines, data output lines and capacity, respectively, as a. 8, 8, 4000 b. 8, 8, 4096 c. 12, 12, 4096 d. 8, 12, 4096

59. Consider the following mapping techniques: 1. Direct mapping 2. Associative mapping 3. Set associative mapping Which of these are used with cache? a. 1, 2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

60. Consider the following statements: 1. Deviation from the true value of the

measured variable is called as error 2. The smallest change in measured value

to which the instrument will respond is called resolution

3. The ratio of output signal or response of the instrument to a change of input or measured variable is called sensitivity.

Which of these statements are correct? a. 1, 2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

61. Two equal resistances, each of 100 2 ± 1% (standard deviation) are connected in parallel. The standard deviation of the parallel combination will be a. 0.5%

b. 1 2%

c. 2% d. 2%

62. The resistance of thermostat is 5000 at 25°C and its resistance temperature co efficiency is 0.041°C. A measurement with a lead resistance of 10 2 will cause an error of a. 0.02°C b. 0.2°C c. 0.1°C d. 0.05°C

63. A 16-bit ADC is used in a DVM. The reference voltage is 5 V. The minimum voltage that could be measured is

a. 16

5

2 1

b. 16

5

2

c. 16

2 5

2 1

d. 16

2 5

2

64. How would a reading 0.6973 V be displayed on a 4½ digit digital voltmeter on its 10 V scale? a. 0.697 b. 0.6973 c. 0.6900 d. 0.7000

65. Match List I (Data acquisition system/Bus structure) with List II (Application) and select the correct answer: List I A. V × I based system B. IEEE — 488 C. Field — bus system D. TCP / IP List II 1. Process control instrumentation 2. Laboratory instrumentation 3. Computer communication 4. Hart-protocol based communication 5. Parallel data communication

A B C D a. 1 5 4 3 b. 2 3 1 5 c. 1 3 4 5 d. 2 5 1 3

66. The series and shunt field windings of a short shunt cumulatively compound d.c. motor get interchanged by mistake. On supplying rated voltage, the motor shall a. Run normally b. Run in the reverse direction c. Run as differentially compounded d. Not run

67.

8 of 13The above figure shows the speed-torque characteristics of the following d.c. motors A. Shunt motor B. Series motor with weak shunt field C. Cumulatively compound motor D. D. Differential compound motor The no-load speed of all the motor is same. Match the type of motors with the corresponding curve using the codes given below:

A B C D a. 1 4 3 2 b. 2 3 4 1 c. 1 3 4 2 d. 2 4 3 1

68.

The above figures illustrate the principle of synchronous motor operation. In order to maintain rotation, the current in the stator-conductor must go through one half cycle in the same time that the field (the rotor) rotates by one pole pitch. For a six-pole motor, its poles must rotate in space by an angle a. 180° b. 120° c. 90° d. 60°

69. In a d.c. motor if the brushes are shifted opposite to its direction of rotation, then a. Commutation is worsened and speed

decreases b. Commutation is improved and speed

decreases c. Commutation is worsened and speed

increases d. Commutation is improved and speed

increases 70. An alternator is operation on infinite bus.

It will develop maximum synchronizing power when it is operating at a. No load b. Full load c. Its steady state stability limit d. Any load

71. The nature of armature reaction in a 3-phase synchronous generator depends on the nature of its load power factor. Match List I (Nature of armature reaction) with List 11 (Nature of load) and select the correct answer:

List I A. Cross – magnetizing B. Partly demagnetizing and partly cross

magnetizing C. Partly magnetizing and partly cross-

magnetizing D. Completely demagnetizing List II 1. Zero p.f. leading 2. Zero pf. lagging 3. Unity p.f. 4. Leading p.f. impedance 5. Lagging p.f. impedance

A B C D a. 2 1 4 3 b. 5 3 2 1 c. 2 3 4 1 d. 5 1 2 3

72. Short circuit ratio of a synchronous machine is the ratio of a. Field current required to. produce rated

voltage on open circuit and rated armature current

b. Field current required to produce rated. armature current on short circuit to that required to produce rated voltage on open circuit

c. Field current required to produce rated voltage on open circuit to that required to produce rated armature current on short circuit

d. Open circuit voltage to short-circuit armature current for the same field current

73. In a three-phase induction motor with increase in load from light to heavy a. Both stator and rotor power factor

increase b. Both stator and rotor power factor

decrease c. Stator power factor increases while

rotor power factor decreases d. Stator power factor decreases while

rotor power factor increases 74. The following performance characteristics

are attributed to a 3-phase cage induction motor without skew:

9 of 131. Lower magnetizing current compared

to a slip ring motor 2. Low efficiency 3. High p.f. 4. Possible cogging and crawling Which of these statements are correct? a. 1, 2 and 3 b. 2, 3 and 4 c. 1, 3 and 4 d. 1, 2 and 4

75. The power input to an induction motor is 50 kW when it is running at 4% slip. If the stator resistance and core losses are neglected, the rotor copper loss is equal to a. 38 kW b. 20 kW c. 4kW d. 2kW

76. In order to control the speed of a slip ring 3-phase induction motor through injected voltage in its rotor circuit, this voltage and the rotor voltage should essentially be a. In same phase b. In quadrate c. In phase opposition d. Of same frequency

77.

The above diagrams show a two-winding transformer (Fig. 1) and an auto-transformer (Fig. 2) formed by reconnection of the terminals of the former. The terminal markings are the conventional ones with regard to the respectively polarities. When operated as an auto-transformer with an input voltage of 500 V, the output load current would be a. 50A b. 40A c. 30A d. 10A

78. A d.c. shunt motor with negligible armature resistance is required to drive a constant power load. Under normal rated-load operating conditions when the terminal voltage Vt=1.0 p.u., the speed n=1.0 p.u. and the armature current Ia= 1.0

p.u. and, with linear magnetizing characteristic the field flux =1.0 p.u. If vt = 0.5 p.u. and the flux is kept constant at 1.0 p.u., then a. 1/ 2 . . 2.0. . .an p u and I p u

b. 1.0 . . 2.0 . .an p u and I p u

c. 2.0 . . 1.0 . .an p u and I p u

d. 1/ 2 . . 1/ 2 . .an p u and I p u

79. Three single-phase transformers with turn ratio 1: 10 are connected in delta star to supply a 3-phase load. The supply voltage is 400 V (line to line). The line voltage on the load side is a. 400V

b. 400 3V c. 4000V

d. 4000 3V 80. Match List I (Pressure head) with List II

(Type of turbine) and select the correct answer: List I A. Low head B. Medium head C. High head List II 1. Kaplan 2. Francis 3. Pelton

A B C a. 1 2 3 b. 3 2 1 c. 2 3 1 d. 2 1 3

81.

A normal two - winding 3-phase delta -delta transformer connection together with the corresponding primary and secondary voltage pharos diagrams are shown above.

10 of 13The magnitude of each of the symmetrical secondary voltages Vab, Vbc and Vca is E. If while connecting the secondary side, the terminals X1 and X2 of the transformer II are interchanged by mistake, the resultant voltage around the secondary closed delta would be a. E b. 1.5E

c. 3E d. 2E

82. For a given base voltage and base volt-amperes, the per unit impedance value of an element is x. The per unit impedance value of this element when the voltage and volt-amperes bases are both doubled will be a. 0.5x b. X c. 2x d. 4x

83. Consider the following statements with respect to an interconnected power system: 1. Frequency will be same at all buses in

the system 2. Voltages can be different at different

buses 3. Both frequency and voltage can be

different at different buses Which of these statements are correct? a. 1, 2 and 3 b. 1 and 3 c. 1 and 2 d. 2 and 3

84. Consider the following statements: Overhead transmission lines are provided with earth wires 1. To protect the transmission line from

direct lightning strike 2. To protect the transmission line

insulation from the indirect lightning strike

3. To balance the line currents 4. To provide path for neutral current Which of these statements is/are correct? a. 1 and 3 b. 1and 4 c. 1 only d. 2 only

85. In Gauss-Seidel method of power flow problem, the number of iterations may be reduced if the correction in voltage at each bus is multiplied by a. Gauss constant

b. Acceleration constant c. Deceleration constant d. Blocking factor

86. Consider the following statements: 1. It is easier to construct the YBUS matrix

as compared to ZBUS 2. ZBUS is a full matrix while YBUS is

sparse 3. YBUS can be easily modified whenever

the network changes as compared to the ZBUS

Which of these statements are correct? a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2 and 3

87. When the wave vector an electron in a metal is equal to half the reciprocal vector values, the electron wave is a. A traveling wave b. A standing wave c. An exponentially decaying wave d. An exponentially rising wave

88. Temperature coefficient of resistively in an intrinsic semiconductor is a. Positive and has a large value b. Negative and has a large value c. Positive and has a small value d. Negative and has a small value

89. When a piece of metal has a temperature gradient between its two ends, and e.m.f. is observed to exist between those ends. This is known as a. Peltier effect b. See beck effect c. Thomson effect d. Hall effect

90. Consider the following factors: 1. Variation of ICBO with temperature 2. Variation of VCE with temperature 3. Variation of VBE with temperature Which of these factors pose/poses the need for proper biasing in a bipolar junction transistor? a. 1, 2 and 3 b. 2 and 3 c. 2 only d. 1 and 3

91. Match List I (Oscillators) with List II (Characteristics) and select the correct answer: List I A. Wein bridge oscillator B. Hartly oscillator

11 of 13C. Crystal oscillator D. Blocking oscillator List II 1. Very good frequency stability 2. Low frequency oscillator used

typically for audio-frequency range 3. Used for generation for pulses 4. Contains two inductors in a resonant

circuit A B C D

a. 2 1 4 3 b. 3 1 4 2 c. 2 4 1 3 d. 3 4 1 2

92.

For the op-amp circuit shown above the output voltage V0 Is a. – 100 mV b. + 100 mV c. + 200 mV d. + 300 mV

93. Consider the following structure for JFET:

If the dimension ‘a’ is halved and ‘b is doubled, then the channel pinch off potential Vp, will become a. Double b. Half c. Four times d. One fourth

94. Which of the following diodes works under forward biased condition? a. Zener diode b. Varactor diode c. Light emitting diode d. Photo diode

95. Which of the following statements is correct? a. The simple equivalent circuit of a

JFET contains a very high resistance RGS between the gate and the source

b. The Tran conductance gm in the equivalent circuit of a JFET is maximum when VGS = 0

c. E bers-Moll model cannot be used for pnp transistor

d. Electron-flow model can be used as equivalent circuit of an npn transistor

96. In an amplifier with feedback, the following effects were observed: Voltage gain decreases, input impedance increases, output impedance decreases and distortion decreases. This is a case of a. Non-inverting voltage feedback b. Non-inverting current feedback c. Inverting voltage feedback d. Inverting current feedback

97. The logic Y AB A B is equivalent to a. Y = AB

b. Y A B c. Y = 1 d. Y = 0

98. Match List I (Type of memory) with List II (Property) and select the correct answer: List I A. Static RAM (SRAM) B. Read only memory (ROM) C. Dynamic RAM (DRAM) List II 1. Non-volatile memory 2. Memory refresh is required 3. Low density memory as memory cell

may have 4 or more transistors A B C

a. 2 3 1 b. 3 2 1 c. 1 3 2 d. 3 1 2

99. Consider the following statements: A monostable multivibrator 1. Can be constructed by using a timer

555 2. Is used to generate a gating pulse

whose width can be controlled 3. Has inherent hysteretic providing

range of value between the low and high switching levels

The correct statement(s) is/are a. 1, 2 and 3 b. 1 and 2 c. 1 only d. 1 and 3

100. Consider the following statements: Shift registers can be realized by using 1. Positive edge triggered f)-flip flops

12 of 132. Negative edge triggered J-K flip flops 3. Level triggered D-flip flops The correct statements (s) is/are a. 1,2 and 3 b. 1 and 2 c. 1 only d. 1 and 3

101.

The circuit shown above is a four bit

a. BCD to Gray code converter b. XS3 to Gray code converter c. Binary to Gray code converter d. Gray code to binary converter

102. Which of the following statements is NOT correct? a. A multiplexer has several data inputs

and a single output b. Two 8 to 1 multiplexer can be

cascaded to obtain one 16 to 1 multiplexer

c. Logic functions can be implemented using multiplexes

d. Multiplexers cannot have open - collector outputs

103. Match List I (Boolean function) with List 11 (Minimum number of two-input NAND gates) and select the correct answer: List I

A. Y ABC ABC

B. Y AB AB C

C. Y AB AB ABC List II 1. Five 2. Four 3. Six

A B C a. 3 1 2 b. 1 3 2 c. 2 1 3 d. 1 2 3

104. The Fourier transform of Signum function is given by a. 2j f b. 1/ 2j f

c. 1

2f

j f

d. 2j f f

105. The autocorrelation R( ) of a periodic function has the following property: a. 0R R

b. 0R R

c. 0R R R

d. 0R R R

106. A generator of 50 internal impedance and operating at 1 GHz feeds a 75 load via a coaxial line of characteristic impedance 50 . The voltage standing wave ratio on the feed line is a. 0.50 b. 1.50 c. 1.75 d. 2.50

107. An analog signal is band limited to Hz, sampled at the Nyquist rate and the samples are quantized into 4 levels. The quantization levels Q1, Q2,Q3 and Q4 (messages) are assumed independent. If they occur with the probability rates P1 = P4=1/8 and P2=P3=3/8, then the information rate of the sauces is a. 10 bits/s b. 5 bits/s c. 3.6 bits/s d. 2 bits/s

108. The Nyquist sampling interval for the signal sin 350 sin 250S t C t c t is

a. 1

350s

b. 350

s

c. 1

175s

d. 175

s

109. In a TV system, ghost images are caused due to a. Co-channel interference b. Adjacent-channel interference c. Multipath transmission d. Improper scanning

110. The main advantage of PCM system is a. Less bandwidth requirement b. Less power requirement

13 of 13c. Better S/N ratio d. Higher depth of modulation

111. When the number of bits per sample in a PCM system is increased by one, the improvement in the signal to quantization noise ratio, in dB, is a. 0 b. 3 c. 6 d. 7

112. In a PCM system, the number of quantization levels is 16 and the maximum signal frequency is 4 kHz; the bit transmission rate is a. 32 bits/s b. 16 bits/s c. 32 kbits/s d. 64 kbits/s

113. A voice frequency analog signal, transmitted over a binary PCM system undergoes the following sequential operations: a. Flat top sampling giving PAM,

Uniform Quantization, Encoding b. Natural sampling giving PAM, Non-

uniform Quantization, Encoding c. Flat top sampling giving PAM, Non-

uniform Quantization, encoding d. Natural sampling giving PAM,

Uniform Quantization, Encoding 114. A sine wave carrier Vc=Vc sin ct is

amplitude modulated by the signal sinm m mV V t so that the modulation

index is unity; then the normalized total power in carrier and side frequencies is given by a. 3/4V2 b. V2 c. 3/2 2

cV

d. 3 2cV

115. Four independent messages have bandwidths of 100 Hz, 100 Hz, 200 Hz and 400 Hz respectively. Each is sampled at the Nyquist rate, time division multiplexed and transmitted. The transmitted sample rate, in Hz, is given by a. 200 b. 400 c. 800 d. 1600

116. Match List I (Process) with list II (Performance) and select the correct answer:

List I A. Commanding B. TDM C. Source coding D. FDM List II 1. To increase the information

transmission rate 2. To use only one carrier frequency to

handle different signals 3. To use different frequency bands for

different signals 4. To protect the small signals in PCM

from quantizing noise A B C D

a. 4 3 1 2 b. 1 2 4 3 c. 4 2 1 3 d. 1 3 4 2

117. While comparing the noise performance of FM, PM, PCM and DSB-SC modulating systems, one finds that linearity is preserved in the following system: a. FM system b. Pm system c. PCM system d. DSB-SC system

118. Gaussian probability density function is

given by 2

22

x mke

. The value of k is

a. 1/ 2

b. 1/ 2

c. 2 d. 2

119. In a cascaded two-stage amplifier, each having a gain of 20 dB and noise figure of 20 dB, the overall noise figure will be a. 20.95 dB b. 22.95 dB c. 40dB d. 400dB

120. The maximum through-put for the slotted ALOHA at the offered channel traffic G is given by a. 0.368 packets per slot at G = 1 b. 0.368 packets per slot at G = ½ c. 0.184 packets per slot at G = 1 d. 0.184 packets per slot at G = ½

1 of 13

1. A single phase fully controlled b ridge is

supplied at 120V rms. What will be the average load voltage for a delay angle of 90° assuming continuous load current? a. 0 V b. 70.4 V c. 102 V d. 170 V

2. A single-phase ac. voltage controlled feeds a pure inductive load. The conduction period of a thyristor for a firing angle of a (in the range 90 180 ) is a. b. 2 c. 2 d. 2

3. A 3-phase inverter is fed from a 600 V source. For a star-connected resistive load 15 Q/phase, the rms load current for 120° conduction is a. 32.66 A b. 16.33A c. 8.16A d. 12.33A

4. Which one of the following pairs is not correctly matched? a. Oxidation : Masking b. Ion-implantation : Doping c. Metallization : Isolation d. Photolithography: Pattering

5. Following methods are used for isolation in IC fabrication: 1. Oxide isolation 2. Resistive isolation 3. P-n junction isolation The correct sequence in the descending order of the magnitude of isolation obtained is a. 3,1,2 b. 1,3,2 c. 1,2,3 d. 3,2,1

6. What is the correct sequence of process steps given below during the fabrication of a polysilicon gate MOSFET? 1. Source and drain diffusion 2. Field oxidation and active area

definition

3. Gate polysilicon deposition and patterning

4. Gate oxidation Select the correct answer using the codes given below: a. 1, 2, 3, 4 b. 1, 4, 3, 2 c. 2,4,3, 1 d. 2, 1,4,3

7. The CZ method in crystal growth provides a. A polycrystalline ingot b. A single crystal ingot with controlled

impurities c. An ingot with irregular arrangement of

atoms d. A single crystal ingot with unwanted

impurities 8. Which of the following are the valid

reasons for polishing silicon wafer used for IC fabrication? 1. To make the surface clean 2. To remove the surface damaged silicon

layers 3. To make the surface flat 4. To improve conductivity of the surface

layers 5. To make both sides more parallel Select the correct answer using the codes given below: a. 1,2 and 3 b. 2,3 and 5 c. 1, 4 and 5 d. 2, 3 and 4

9. 30% KQH solution is used to etch (100) oriented silicon through a 100 m × 100 m square window. The other regions of silicon (outside the window) are protected by a mask and do not get etched. The etch profile will have a. Isotropic contour b. Vertical side wall c. Severe undercut d. AV – groove shape

10. Consider the following statements 1. Lou-implantation is less prone to

contamination compared to diffusion. 2. In diffusion, the peak impurity

concentration is always located at the

C.S.E Pre-2003


2 of 13surface while in ion-implantation peak position can be tailored.

3. Ion-implantation is a simpler and less expensive process than diffusion.

4. The substrate is damaged after ion-implantation.

Which of these statements are correct? a. 1 and 2 b. 2 and 3 c. 1,2 and 4 d. 1,3 and 4

11. The main advantage of plasma-assisted chemical vapour deposition process over ordinary chemical vapour deposition is a. Plasma-assisted deposition is faster b. Plasma-assisted deposition results in

films with better stoichiometry c. Deposition rate is controlled better in a

plasma- assisted process d. The deposition temperature is much

less in a plasma- assisted process 12. After the circuit elements are fabricated in

an IC and the surface is passivated , a pattern of Al film is deposited using photolithography to a. Connect the various terminals of

circuit components in a predetermined way

b. Protect the surface form oxidation due to atmospheric exposure

c. Protect a metal surface to be used as heat sink

d. Provide a metal surface for bonding the chip

13. Consider the following statements about Fermi energy in a metal: 1. It is the energy of the highest occupied

electron state at zero Kelvin. 2. It is the energy level of electrons at

which probability of occupation is one half at any temperature.

3. At temperature above zero Kelvin, some of the energy states above Fermi energy are occupied and some states below it are empty.

Which of these statements is/are correct? a. 1, 2 and 3 b. Only 2 c. Only 1 d. 2 and 3

14. Match List I with List II and select the correct answer: List I A. Continuity equation

B. Poisson’s equation C. Einstein’s equation D. Diffusion current equation List II 1. Electric field intensity with charge

density 2. Minority carrier diffusion constant

with mobility 3. Minority carrier concentration gradient 4. Time rate of change of minority carrier

density A B C D

a. 4 3 2 1 b. 2 1 4 3 c. 4 1 2 3 d. 2 3 4 1

15.

For the given circuit, 3 /rad s if V is

taken as reference, the phasor of I is given by a. 1 90 b. 3 90 c. 5 60

d. 2 45 16.

For the given a.c. circuit if the value of C

is chosen such that V and I are in phase, then I1 lead I2 by an angle given by a. 0° b. 45° c. 90° d. 135°

17.

For the given circuit, if

3 of 13

160sin 10v t t and

5sin 20 ,i t t then the reactive

power absorbed by the black box N is given by8 a. 50 Vars b. 100 Vars c. 400 Vars d. 200 Vars

18.

The switch in the circuit is closed at t = 0.

The current through the battery at t = 0+ and t is, respectively a. 10A and 10A b. 0A and 10A c. 10A and 0A d. 0A and 0A

19. The Laplace transform of the voltage across the capacitor of 0.5F is

3 2

1

1

sV s

s s s

Then the value of the current through the capacitor at (t=0+ is give4n by a. 0A b. 0.5 A c. 1.0 A d. 1.5 A

20. If u(t) and (t) are the step function and the impulse function respectively at t = 0, then the Laplace transform of the function f(t) = u(t –1) (t) is equal to a. 1 b. 1/s c. 0

d. 1

1s

21. An ac. sinusoidal voltage source is connected across a series circuit consisting of a resistor and a capacitor. The rms value of the voltage across the resistor and capacitor are 100 V and 200V respectively. The rms value of the voltage of the source is a. 300V

b. 100 5V

c. 100 3V

d. 100V 22.

The frequency response for a network

function H(s) is given above H(s) is given by

a. 1

s

s

b. 10

1

s

s

c. 10

1s

d.

1

1s s

23. Consider the signals 1 2sin cos 4X t t t and

2 sin 5 3sin13X t t t

a. Both the signals are periodic b. Both the signals are not periodic c. X1 is periodic, but X2 is not periodic d. X1 is not periodic, but X2 is periodic

24. Which one of the following pairs is not correctly matched?

(System attribute of the Discrete-Time system)

{System Description with input ×(n) and output y{n}

a. Causal : 1Y n X n

b. Linear : 3 2Y n n

c. Stable : 2 5 1Y n n n

d. Time-invariant : 21Y n X n

25. The step response of a system is 2 31 5 10 6t t tC t e e e . The impulse

response of the system is a. 2 35 20 18t t te e e b. 2 35 20 18t t te e e c. 2 35 20 18t t te e e d. 2 35 20 18t t te e e

26. Which one of the following is a linear system? a. 2y t u t

b. 2 5y t u t

4 of 13c. 22y t u t

d. 22 5y t u t

27. The system 2

0.8

2G s

s s

is excited by

a unit step input. The steady state output is a. 0.8 b. 0.4 c. -0.4 d. Unbounded

28. The Laplace transform of coste t is

a.

2 2

s

s

b.

2 2

s

s

c.

2 2

s

s

d.

2 2

s

s

29. Match List I with List II and select the correct answer: List I (Function) A. atte B. x at

C. Z Y t Z dz

D. d t

dt

List II (Laplace Transform) 1. sX s

2. X s Y s

3. 2

1

s a

4. X s

s

5. 1 s

a a

A B C D a. 1 2 4 3 b. 3 5 2 1 c. 1 5 2 3 d. 3 2 4 1

30. Given a unity feedback system with

4

KG s

s s

, the value of K for

damping ratio of 0.5 is a. 1

b. 16 c. 4 d. 2

31. A unity feedback control system has forward path transfer function G(s) given

by 2

10 1

12 5

sG s

s s s

The steady-state error due to unit parabolic input r(t) = t2/2U (t) is a. Zero b. 0.1 c. 1.0 d. Infinite

32. For the control system with

2

2

2 3

K sG s H s

s s s

The type number is a. 1 b. 2 c. 3 d. 4

33. The root locus plot of a system having open loop transfer function

3

10 70

100 200

K s sG s H s

s s s

will

have angle of asymptotes as a. 60°, 100° b. 60°,180°,300° c. 60°,120°,180° d. 60°,90°,120°

34. Consider the equation: 4 3 22 3 5 10 0s s s s The number of roots this equation has in the right-half of s-plane is a. One b. Two c. Three d. Four

35.

The feedback system shown above is

stable for all values of K given by a. K>0 b. K<0 c. 0<K<42 d. 0<k<60

5 of 1336. The Nyquist plot of a system passes

through (–1 j 0) point in the GH plane The phase margin of the system is a. > 0 b. Zero c. < 0 d. Infinite

37. A plane wave propagates in a direction

having direction cosines 1/ 2,1/ 2,0 .

The equation of the phase fronts is a. XY = Constant b. X/Y= constant c. X+Y = constant d. X-Y constant

38. Which one of the following modes does not exists in a rectangular waveguide? a. TM11 b. TE10 c. TE01 d. TM10

39. A parallel plate waveguide has a plate spacing of 10 mm and is filled completely with a dielectric medium of relative permittivity 9.0. The cut-ott frequency of the first (lowest) TE mode is a. 1.0 GHz b. 2.5 GHz c. 5.0GHz d. 10.0GHz

40. The unit normal to the equipotent surface constant C is, in general given by a.

b. | |

c. | |

d. | |

41.

For sinusoidal input voltage having a peak

value m RV V the output for the given

circuit will be

42. A voltage series feedback has

a. High input impedance b. Low input impedance c. High output impedance d. High voltage gain

43.

The current in the meter (M) in the op-amp circuit shown is a. 1mA b. 100 A c. 2mA d. 200 A

44. ` CD CD CD CD

AB 0 0 1 0

AB 1 1 1 1

AB 1 1 0 0

AB 0 0 0 0

In the Karnaugh map shown above, the minimal output X is

a. X ABCD AB ABC

b. X BC AB ACD

c. X BCD ACD ABC ABCD

d. X BC AC 45. EPROM, memory content can be erased

by exposing it to a. UV light b. Intense heat radiation c. IR rays d. Microwaves

6 of 1346. The number of memory chips of size

1K×4-bits required to build a memory bank of size 16K×8-bits is a. 64 b. 32 c. 16 d. 8

47.

For the rectifier circuit shown, the PIV of the diode is a. Vm

b. 2 mV

c. /mV

d. 2Vm 48. Match List I (Name of Memory) with List

II (Features/ Characteristics) and select the correct answer: List I A. SRAM B. ROM C. PLA D. DRAM List II 1. This contains conventional storage like

latches (BJT or MOSFET) and it is non-volatile

2. This contains conventional storage like latches (BJT or MOSFET) and has both Read and Write operation

3. This contains a set of AND, OR or INVERT logic gates and can be programmed

4. This contains only MOSFETs and needs periodic refreshing

A B C D a. 3 4 2 1 b. 2 1 3 4 c. 3 1 2 4 d. 2 4 3 1

49. The binary number 000001011 when represented in BCD format, is given by a. 00001011 b. 10111011 c. 000100001 d. 10001000


1. A t-bit magnitude comparator for inputs A=A3A2A0 and B=B3B2B1B0 has three outputs A>B, A=B and B>A.

2. Two t-bit comparators an be cascaded to create an 8-bit comparator.

3. The basic building block of a comparator is the4 coincidence (exclusive-NOR) gate.

Which of these statements is/are correct? a. 1,2 and 3 b. 1 and 2 c. Only 1 d. Only 3

51. The auto-correlation function of the white Gaussian noise is a. A constant b. A step function c. An impulse function d. An exponential function

52. Which one of the following pulses has the same form in time domain as well as in frequency domain? a. Rectangular pulse b. Exponential pulse c. Triangular pulse d. Gaussian pulse

53. Good voice reproduction via PCM requires 128 quantization levels. If the bandwidth of voice channel is 4 kHz, the data rate is a. 256 kbps b. 128 kbps c. 56 kbps d. 28 kbps

54. In a transformer the frequency of the input voltage is doubled. Hysteretic loss at the higher frequency in terms of that at the lower frequency is a. Doubled b. Halved c. Four times d. One-fourth

55. Two semiconductor materials A and B have carrier concentration values nA=1×1021m-3 and nB=4×1021m-3. Hall coefficients of the material, RA and RB are in the ratio a. 1:2 b. 2:1 c. 1:4 d. 4:1

56. Consider the following materials: 1. Pure silicon 2. Aluminum 3. Doped silicon

7 of 134. Mica The correct sequence in the order of their increasing electrical resistively is a. 1,2,3,4 b. 2,3,4,1 c. 2,3,1,4 d. 1,3,4,2

57. There are four contributors to total polarization of a material. These contributions are electronic, ionic, dipolar and space-charge polarization. At optical frequencies the only major contribution to polarization is from a. Electronic polarization b. Ionic polarization c. Dipolar polarization d. Space-charge polarization

58. For electrons and holes, the Hall coefficients are a. Both positive b. Both negative c. Positive and negative, respectively d. Negative and positive, respectively

59. Three single-phase transformers, each of 100 kVA rating are connected in delta. If one of the transformers is taken out of service, the capacity of the system Will be a. 200 kVA b. 1732 kVA c. 115.5 kVA d. 36.6 kVA

60. Three units of 1 : 5 transformers are connected in –Y to supply a 3-phase load from a 400 V. 3- phase source. The line voltage on the load side is a. 1000 V b. 80 V c. 3464 V d. 803 V

61. A 15 MVA, 33/11 kV, 3-phase transformer having an impedance of 16 on the high tension side is supplied from a generator rated 30 MVA, 11 kV. The p.u. impedances of the transformer calculated on its own base and on the generator base will be in the ratio a. 1 : 1 b. 1 : 3 c. 1 : 9 d. 1 : 18

62. Steady state operating condition of a power system indicates a. A situation when the connected load is

absolutely constant

b. A situation when the generated power is absolutely constant

c. A situation when both connected load and generated power are equal to each other and remain constant

d. An equilibrium state around which small fluctuations in power, both in generation and load, occur all the time

63. Match List I (Insulation Type) with List II (Purpose or Configuration) and select the correct answer: List I A. Pin type B. Suspension type C. Strain type D. Shackle type List II 1. Low voltage distribution lines 2. String of insulator in horizontal

position 3. String of insulators in vertical position 4. For voltage up to 33 kV

A B C D a. 4 2 3 1 b. 1 3 2 4 c. 4 3 2 1 d. 1 2 3 4

64. Match List I with List II and select the correct answer: List I (Bus Types) A. Load bus B. Generator bus C. Slack bus List II (Pairs of variables) 1. P and V 2. P and Q 3. V and S

A B C a. 1 2 3 b. 2 3 1 c. 1 3 2 d. 2 1 3

65. Match List I with List II and select the correct answer: List I (Relays) A. Buchholz relay B. Tran slay relay C. Carrier current phase comparison relay D. Directional over current relay List II (Protection) 1. Feeder 2. Transformer 3. Ring main distributor 4. Long overhead transmission line

8 of 13A B C D

a. 2 3 4 1 b. 4 1 2 3 c. 2 1 4 3 d. 4 3 2 1

66. The resolution of a 3% digit voltmeter on 1 V range is a. 0.1 b. 0.01 c. 0.001 d. 0.0001

67. Vacuum cleaners are a. Permanent magnet f.h.p. motors b. Single-phase capacitor motor with

direct-on-line start c. Reluctance motor d. Universal motor

68. Assertion (A): A dipole of length 30 mm operated at a frequency of 100 MHz is an efficient radiator. Reason (R): A Hertz Ian dipole is an inefficient radiator since its radiation resistance is very low. a. Both A and R are individually true and

R is the correct explanation of A b. Both A and R are individually true but

R is not the correct explanations of A c. A is true but R is false d. A is false but R is true

69. Assertion (A): A circularly polarized wave incident at the Brewster angle becomes linearly polarized. Reason (R): A wave composed of both parallel and perpendicular components incident at Brewster angle produces a reflected wave with only E component polarized parallel to the interface a. Both A and R are individually true and



70. Assertion (A): A clipper circuit can be realized using two biased diodes in shunt Reason (R): A clipper circuit slices the input waveform between two preset voltage levels. a. Both A and R are individually true and



71. Assertion (A): Three state logic is used when we want to connect more than one input/output devices to the same data bus in a digital system bus. Reason (R): Three stage logic has a high impedance, state which helps in isolating the input/output device from the data bus. a. Both A and R are individually true and



72. Assertion (A): When large amount of data is to be printed out from the memory of a computer DMA is used. Reason (R): DMA avoids using the CPU thus allowing the CPU to attend to another job. a. Both A and R are individually true and



73. Assertion (A): In general, moving iron voltmeters are less accurate than those of the dynamometer type. Reason (R): Moving on voltmeters often use air- friction damping. a. Both A and R are individually true and



74. Assertion (A): The exciting current of a single phase transformer with sinusoidal voltage supply is non-sinusoidal. Reason (R): Eddy currents induced in the transformer core are non-sinusoidal introducing harmonics of higher order in the exciting current. a. Both A and R are individually true and



75. Assertion (A): A self-controlled synchronous motor fed from a load commuted CSI is free from hunting and stability problems.

9 of 13Reason (R): The motor has damper windings. a. Both A and R are individually true and



76. Assertion (A): Lightly doped drain (LDD) MOSFETs are less prone to hot electron effects. Reason (R): The maximum electric field in the channel is less in lightly doped drain devices. a. Both A and R are individually true and



77. Assertion (A): For a symmetrical magnetic field distribution under each pole and for equal number of armature conductors per parallel path, the emf available between adjacent brushes of a lap-wound d.c. machine is equal for each of the parallel paths. Reason (R): The instantaneous emf induced in each conductor of each parallel path is equal for all the conductors. a. Both A and R are individually true and



78. Assertion (A): In a load flow study, the rated frequency of the power system does not appear in the power flow equations. Reason (R): Rated frequency of the system is automatically assured when active power balance is obtained through toad flow studies. a. Both A and R are individually true and



79. Assertion (A): High pressure oxidation technique reduces crystalline defects and affects the previous diffusion profiles to a very little extent.

Reason (R): The high pressure oxidation processing is a relatively ‘4ower temperature phenomenon. a. Both A and R are individually true and



80. Assertion (A): A half-controlled converter has improved power factor on the line side. Reason (R): During free-wheeling of the converter, a part of the energy stored in the inductance is utilized as active power in the load. a. Both A and R are individually true and



81. A binary source generates two messages with probabilities P0 and 1 1 01P P P .The entropy of this source

is a. 1-bit/symbol irrespective of the value

of P1 b. Maximum when P0 = 0 c. Maximum when P1 = P0 d. Minimum when P1= P0

82. A RF signal is amplitude modulated to a depth of 100% by a sinusoidal signal. The ratio of modulated signal power to unpopulated carrier power is a. 1 b. 2 c. 2/3 d. 3/2

83. The antenna current of an AM broadcast transmitter modulated to a depth of 100%

by an audio sine wave is 3 / 2 A which

increases to 2 A due to simultaneous modulation by another audio sine wave. The modulation index due to the second sine wave is a. 0.5 b. 0.707 c. 1.0 d. 0.866

84. The frequency deviation produced in a VHF carrier by a signal of 100 Hz is 50 kHz. The frequency modulation index is

10 of 13a. 100 radians b. 250 radians c. 500 radians d. 750 radians

85. The probability density function of the envelope of a sinusoidal signal along with narrow band noise follows the following distribution a. Gaussian b. Rayleigh c. Rician d. Poisson

86. The approximate height of a geostationary satellite above the Earth’s surface is a. 1000 km b. 10000 km c. 20000 km d. 40000 km

87. The instrument landing system (ILS) and the ground controlled approach (GCA) system of landing, use a. Glide path localizer and two radars,

respectively b. Master and slave stations for both c. Glide path localizer for both

88. If (327)9 = (X)5, then the value of X is given by a. 327 b. 268 c. 2033 d. 3302

89. The decimal number 4097 is represented in four forms as shown below. Match List I (Type of Representation) with List II (Number) and select the correct answer: List I A. Binary B. BCD C. Octal D. Hexadecimal List II 1. 000000000000 1001 2. 0000 0000 0001 0001 3. 0001 0000 0000 0001 4. 01000000 10010111

A B C D a. 3 1 2 4 b. 2 4 3 1 c. 3 4 2 1 d. 2 1 3 4

90. Consider the following statements: Multiplication in a computer can be performed by using 1. A hardware multiplier

2. Successive addition in an adder 3. Shift and add technique Which of these statements are correct? a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

91. Which one of the following logic families is the fastest? a. 12L b. ECL c. TTL d. CMOS

92. The process of organizing the memory into two banks to allow 8-bit and 16-bit data operating is called a. Bank switching b. Indexed mapping c. 2-way memory interleaving d. Memory segmentation

93. If any block of a main memory could reside in any block of a cache, the mapping technique used is a. Direct mapping b. Associative mapping c. Set-associative mapping d. Linear mapping

94. DAA is an instruction in the instruction set of many microprocessors. This instruction is used in a microprocessor to perform a. Binary addition b. BCD addition c. ASCII addition d. Binary subtraction

95. It is desired to reserve a word (two consecutive bytes) in the memory and initialize it to the value 1945. Then we use the assembler directive a. S : DS 1945 b. T : DB 1945 c. Q : DW 1945 d. F : EQU 1945

96. Which of the following I/O methods does not use the CPU for performing I/O operation? a. Program initiated I/O b. Device initiated I/O c. Direct memory access d. Serial I/O

97. Match List I with List II and select the correct answer: List I (Bridge Circuit) A. Hay’s bridge B. Kelvin’s double bridge

11 of 13C. Schering bridge D. Wheatstone bridge List II (Measured Parameter) 1. Low resistance 2. Medium resistance 3. High 0 inductance 4. Capacitance

A B C D a. 4 1 3 2 b. 3 2 4 1 c. 4 2 3 1 d. 3 1 4 2

98.

If two 300 V full-scale voltmeter V1 and V2 having sensitivities of 100 k / V and 150 k / V respectively are connected in series to measure 500 V, then a. V1 and V2 will read 250 V each b. V1 will read 200 V and V2 will read

300V c. V1 will read 300 V and V2 will read

200 V d. V1 and V2 will read 0V each

99. In eddy current damping systems, the disc employed should be of a. Conducting and magnetic material b. Conducting but non-magnetic material c. Magnetic but non-conducting material d. Non-conducting and non-magnetic

material 100. An instrument that measures the insulation

resistance of systems using a self-provided 1000 V dc. generator is called a. VTVM b. Meggar c. Thermocouple instrument d. Multi Mate

101. Which one of the following variables cannot be measured directly by a CRO? a. Current b. Voltage c. Phase difference d. Frequency

102.

The waveform given above is observed on the screen of a CR0. If the time/div switch is set at 10 gs and the volt/div at 200 mV, the frequency and peak to peak voltage are. Respectively a. 33 33 kHz, 800 mV b. 25 kHz, 600 mV c. 33.33 kHz, 600 mV d. 25 kHz, 400 mV

103.

The circuit shown above is that of a MultiMate measuring a.c. voltage Consider the following statements 1. Diode D1 conducts during the positive

half cycle. 2. The shunt resistance is used so that

diode D1 conducts heavily and moves the operating point in the linear portion of V –1 characteristic of diode D1.

3. Diode D2 conducts during negative half cycle and current bypasses the meter.

Which of these statements are correct? a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1,2 and 3

104. In a low power factor wattmeter, sometimes compensating coil is employed in order to a. Neutralize the capacitive effect of

pressure coil b. Compensate for the inductance of

pressure coil c. Compensate for the error caused by

power loss in the pressure coil d. Reduce the error caused by eddy

current damping

12 of 13105. If a 47 to 53 Hz reed type frequency meter

is provided with polarizing winding excited by d.c., the new range of frequency meter is a. 94 to 106 Hz b. 23.5 to 26.5 Hz c. 47 to 53 Hz d. 44 to 50 Hz

106. Field winding of a 4-pole separately excited dc. Machine is excited from a 50 Hz supply. Armature is rotated at 1500 rpm and the brush-rocker is also rotated in the same direction at the same speed. Voltage across the brushes is a. 100Hza.c. b. 50 Hz a.c. c. 50 Hz a.c. with a d.c. component d. Zero

107. Which of the following information is obtained by Potier’s method using open circuit characteristic and zero power factors characteristic? a. Field current equivalent of armature

reaction b. Synchronous reactance c. Leakage reactance d. Leakage reactance and field current

equivalent of armature reaction 108. Match List I with List II and select the

correct answer: List I (Test) A. Slip test B. Open circuit and zero power factor test C. Surnpner’s test D. Swinburne’s test List II 1. Determination of constant losses of a

d.c. shunt machine 2. Determination of efficiency and

regulation of transformer 3. Determination of synchronous Potiere

reactance of synchronous machine 4. Determination of direct and quadrate-

axis synchronous reactance’s of salient pole synchronous machine

A B C D a. 2 1 3 4 b. 4 3 1 2 c. 2 3 1 4’ d. 4 1 3 2

109. Consider the following statements in respect of compensating windings in d.c. motors:

1. Compensating windings are connected in series with the armature

2. Compensating windings aid commutation

3. Compensating windings produce mmf in the same direction as that of armature mmf.

Which of these statements is/are correct? a. 2 and 3 b. Only 1 c. 1 and 3 d. 1 and 2

110. Under variable frequency operation of 3-phase induction motor, air gap flux is kept constant by adjusting the motor voltage For constant air gap flux, machine develops the same torque when the a. Slip is kept constant b. Slip speed is kept constant c. Power flow across the air gap is kept

constant d. Power input to the stator is kept

constant 111.

Figure shows the phase winding connections of a bank of three single-phase transformers. For unity turn ratio and balanced three-phase supply voltage V (line-to-line), voltage between the terminals a2 and c2 on the secondary side will be

a. 3V b. 3V c. V d. 2V

112. The full-load copper loss of a transformer is twice its core loss. At what percent of the full-load will the efficiency be maximum? a. 25% b. 50% c. 70.7% d. 141%

113. Conventional power frequency equivalent circuit of a two-coiled transformer is obtained on the assumption of

13 of 13a. Equal primary and secondary ampere

turns b. Negligible mutual reactance c. Uniform voltage drop along the

windings d. Presence of leakage current between

the windings 114. A separately excited d.c. motor takes a

current I at a speed N. If it draws a current 1/3 at a speed 3N, then this condition is obtained with a. Field control under constant torque b. Voltage control under constant torque c. Field control under constant output d. Voltage control under constant output

115. Consider the following statements: Specific features of BJT are 1. Very small on-state resistance 2. Presence of second breakdown 3. Infinite input resistance 4. Good performance in parallel

operation Which of these statements are correct? a. 1,2, 3 and 4 b. 1,2 and 3 c. 3 and 4 d. 1 and 2

116. Match List I with List Il and select the correct answer: List I (Power Device) A. Thyristor B. MOSFET C. IGBT D. BJT List II (Property) 1. Second breakdown 2. Large on-stage drop 3. Small on-state drop 4. Slow device

A B C D a. 4 3 2 1 b. 1 2 3 4 c. 4 2 3 1 d. 1 3 2 4

117. The on-stage voltage of a GTO is a. 0.7V b. 1–2V c. 2–3V d. >3V

118. A d.c. chopper has an average value of load current of 10 A while feeding a pure resistive load at a given time ratio and frequency. If a large inductance is placed in series with the load resistance and

operated at the same switching frequency and the same time ratio, then the average load current a. Remains constant at 10 A b. Becomes less than 10 A c. Becomes greater than 10 A d. Variation cannot be estimated without

knowing the value of inductance 119. A chopper circuit is operating on TRC

principle at a frequency of 2 kHz on a 220 V d.c. supply. If the load voltage is 170 V, the conduction and blocking period of the thyristor in each cycle are, respectively a. 3.86 s and 1,14 s b. 38.6 ms and 11.4 ms c. 3.86 ms and 1.14 ms d. 0.386 ms and 0.114 ms

120.

Single-phase fully controlled converter shown in the figure is able to feed back load power to the source if the firing angle is varied from a. 0 to 90° and the switches S1 and S2, are

closed b. 0 to 900 and the switches S3 and S4 are

closed c. 90° to 180° and the switches S1 and S2

are closed d. 90° to 180° and the switches S3 and S4

are closed

1 of 14

1. There are two time functions g1(t) and g2(t)

with Fourier transforms G1(f) and G2 (f) repetitively. Fourier transform of a.g1 (t) + b.g2 (t) will be (a and b in the expression are constant) a. The convolution of a G1 (f) and bG2 (f) b. The product of a G1 (f) and bG2 (f) c. The sum of a. G1 (f) and bG2 (f)

d. The product of 1G f

a and

2G f

b

2. Bandwidth of a frequency modulated signal is a. Zero b. The frequency of the modulating signal c. Twice the frequency of modulating

signal d. Infinity

3. The balance equation

. .Z A B A B can be realized using only a. AND gates b. OR gates c. NAND gates d. NOT gates

4. Current drain form the power supply is lowest in which one of the following digital IC logic family? a. TTL b. ECL c. MOS d. CMOS

5. A MOSFET with poly silicon gate is preferred to a MOSFET with aluminum gate since in the first case the a. Device becomes more resistant to

radiation b. Gate can be self-aligned to source and

drain c. Isolation between adjacent devices is

better d. Gate leakage current is smaller

6. In semiconductor wafer cleaning, trichloroethylene is used to remove a. Dust particles from the surface b. Grease from the surface c. Impurities from within the crystal d. Moisture from the surface

7. Work function is a. Minimum temperature at which

thermion emission occurs b. Minimum excess energy needed for

thermion emission c. Maximum temperature up to which

thermion emission occurs d. Optimum energy for thermion

emission 8. For a p-type semiconductor. Fermi level

lies a. In the middle of the energy gap b. Close to the bottom of the conduction

band c. Close to the top of the conduction band d. Close to the top of the valence band

9. The force between a charge q and a grounded infinite conducting place kept ay a distance d form it is given by

a. 2

04

q

d

b. 2

204

q

d

c. 2

016

q

d

d. 2

2016

q

d

10. In a source-free imperfect dielectric medium (specified by loss tangent tan ), Maxwell’s curl equation can be written as:

a. 1 tanH j E j

b. 1 tanH j E j

c. 1 tanH j E j

d. 1 tanH j E j

11. If we have a control system which is actually unstable of has too low gain or phase-margins, then for a more satisfactory performance of the system, we should report to which of the following? 1. reduce the gain of the amplifier 2. Incorporate the phase advance circuit

in the system

C.S.E Pre-2004


2 of 143. Use integral error compensation in the

system Select the correct answer using the codes given by a. 1,2 and 3 b. 1 and 2 c. 1 and 3 d. 2 and 3

12. For a fixed choice of steady-state velocity-error, the use of derivative output compensation in a proportional second order control system increases which of the following? 1. Setting time 2. Undraped natural frequency 3. Damping ratio Select the correct answer using the codes given belo9w: a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

13. If jz re , then which of the following is not correct?

a. *

2cos

z zr

b. *

2 cos

z zr

j

c. *r zz

d. *

zr

z

14.

What is the fundamental frequency of the

discrete-time square wave shown in the figure? a. radian b. /2 radian c. /4 radian d. 0 radian

15.

In the figure shown, the box N contains resistors only E=1 volt and 0 volt; I = 0A and 2AV=3 volts and 2 volts; respectively. If E =1 volt, and I is replaced by 2R , V is equal to a. 1 volts b. 2 volts c. 3 volts d. 4 volts

16.

In the circuit shown, the initial voltage on

the capacitor v(0) =2 V and I is a unit step current source. The voltage across the capacitor, v(t) for t > 0 is

a. 21 TE b. 21 TE c. 2 TE d. 2 te

17. The main reason for connecting a pulse transformer at a output stage of a thyristor triggering circuit is to a. Amplify the power of the triggering

pulse b. Provide electrical isolation c. Reduce the turn-on time of the

thyristor d. Avoid spurious triggering of the

thyristor due to noise 18. Resonant converters are basically used to

a. Generate large peaky voltages b. Reduce the switching losses c. Eliminate harmonics d. Convert a square wave into a sine

wave 19.

3 of 14

In the circuit shown, function of diode D2

is a. To avoid the saturation of the

operational amplifier b. To provide the negative feedback when

the input is negative c. To reduce the reverse breakdown

voltage of D1 d. Insignificant and can be removed

20.

For the circuit shown in the figure, which one of the following waveforms represents the correct output?

21. For a lossless two winding single-phase

transformer on NO-LOAD, the following four phasor diagrams A, B, C and D are considered. Standard symbols are being used to represent the voltage, current and flux.

Which is the correct phasor-diagram? a. A b. B c. C d. D

22.

A normal connected 3 phase transformer is obtained by connecting three single-phase transformers I, II and III as shown above. If transformer III is removed, the system would not operate in “one-delta” mode. Under this condition, if voltage Vab is designed by 60V , the voltage caV is

a. 60V b. 180V c. 180V d. 60V

23. A three-phase 50 Hz transmission line has a capacitance of line to neutral = 0.01 /F km . The voltage of the line is 100 kV. The charging current per kilometer of line is

a. 314

/3

A km

b. 3

314/

3 10A km

c. 33 10

/314

A km

d. 33 10 /A km

24.

4 of 14For the power system network shown, the zero-sequence reactance’s in pu. are indicated. The zero-sequence driving point reactance of bus 3 in p.u. is a. 0.12 b. 0.30 c. 0.10 d. 0.20

25. Which of the following are the advantages of a hard wired control over a micro programmed control? 1. It uses less hardware 2. It generates control signal faster 3. It is more reliable Select the correct answer using the codes given below a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1,2 and 3

26. Which one of the following memories is volatile? a. ROM b. EPROM c. Static RAM d. None of the above

27. Match List I with List II and select the correct answer: List I A. Wien Bridge B. 3-Voltmeter method C. Tn-vector meter D. Watt-hour meter List II 1. Power 2. Frequency 3. Phase 4. Maximum demand 5. Energy

A B C D a. 2 1 4 5 b. 4 5 3 1 c. 2 5 4 1 d. 4 1 3 5

28. Match List I with List H and select the correct answer: List I A. Wien bridge B. Maxwell bridge C. Schering bridge

D. Anderson bridge List II 1. Measurement of resistance 2. High Q inductors 3. Measurement of frequency 4. HV capacitors 5. Low Q inductors

A B C D a. 4 5 3 2 b. 3 2 4 1 c. 4 2 3 1 d. 3 5 4 2

29. Consider the following statements in respect of a solar cell 1. A solar cell is a large area p-n junction 2. In a solar cell the p-n junction is near

the surface 3. A solar cell is a photovoltaic device Which of the statements given above are correct? a. 1, 2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

30. An electrical network used as lag compensator has compensating pole and zero at pc and ZC respectively. Then, they must satisfy which of the following conditions with respect to the S-plane? a. P is in LHS and Zc is in RHS b. Z is in LHS and PC is in RHS c. Both are in LHS and ZC < PC d. Both are in LHS and Zc> Pc

31. The open loop transfer function of a unity

feedback system is given as 1

1G s

s

.

The bandwidth for this system, under open loop and closed loop operations are respectively a. 0.5 and 1.0 rad/s b. 1.0 and 0.5 rad/s c. 1.0 and 2.0 rad/s d. 2.0 and 1.0 rad/s

32. Match List I (Time Domain Specification) with List II (Equation for Finding its Value) and select the correct answer: List I A. Peak overshoot B. Peak time C. Rise time

5 of 14D. Setting time (2%) List II

1. 2/ 1n

2. 4 / n

3. 2exp / 1

4. 1 2cos / 1n

A B C D a. 3 2 4 1 b. 4 1 3 2 c. 3 1 4 2 d. 4 2 3 1

33. The average value of the waveform x(t) = 4 cos 4t — 5 sin 5t is a. 0

b. 2 /

c. 2 / d. 20 /

34. A reciprocal two port network is symmetrical if a. Z11 = z22 b. 1A

c. A D d. 1y

35. If an RC impedance function, Z(s), has equal number of poles and zeros at finite locations, then

a. 0Z Z

b. 0Z Z

c. 0Z Z

d. 0Z Z

36. A single-phase full-bridge, voltage source inverter, feeds a pure inductive load L and the inverter input voltage is Vs. The current through L, with a period of T second, would be a a. Triangular wave with peak value Vs/L .

T/2 b. Triangular wave with peak value VS/L

T/4 c. Square wave with peak value Vs/L T/2 d. Pulsed wave with peak value Vs/L .

T/2

37. Match List I (Power converters) with List II (Industrial Drive) and select the correct answer: List I A. Dual converter B. DC chopper C. Cyclo converter D. Inverter List II 1. Cement klin drive 2. Induction heating 3. Rolling mill drive 4. Electrical vehicle 5. Sugar mills

A B C D a. 2 1 5 3 b. 3 4 1 2 c. 2 4 1 3 d. 3 1 5 2

38. Consider the following statements: Biasing of electronic devices is done 1. To Whom It May Concern: establish

the operating point 2. To make the operating point stable 3. To use the devices as switches rather

than amplifiers Which of the statements given above is/are correct? a. 1 only b. 2 only c. 1 and 2 d. 1, 2 and 3

39. A differential amplifier is basically a/an a. DC amplifier b. AC amplifier c. Chopper amplifier d. Mixer amplifier

40. The number of flags affected when a data-transfer instruction is executed by 8085 is a. 0 b. 1 c. 3 d. 5

41. The Program Counter in a computer is a special purpose register which contains a. The instruction being executed b. The address of the instruction being

executed c. The next instruction to be expected

6 of 14d. The address of the next instruction to

be executed 42. A 5-h.p., 3-phase, 400 V, 4-pole, 50 Hz

squirrel-cage induction motor has a full-load speed of 1440 r.p.m. At half full-load, the speed of this motor would be a. 1480rp.m. b. 1470rpm. c. 1460r.p.m. d. 1450rpm.

43. For a repulsion-type single-phase induction motor four configurations of the brush-axis in relation to the stator-field axis at an instant are considered. The brush-axis is: A. In line with the stator field-axis B. In quadrate with the stator field-axis C. Shifted forward by an angle

,0 90

D. Shifted backward by an angle ,0 90

Indicate from the following code the correct values of developed torque the above motioned positions:

44. The output of a diode detector contains

a. The modulating signal b. The DC voltage c. The RF ripple d. All of the above

45. Which one of the following does not give a digital output? a. Pulse amplitude modulation b. Pulse code modulation c. Differential pulse code modulation d. Delta modulation

46.

In QPSK modulator shown above, the blocks 1, 2 and 3 are, respectively

a. Serial to parallel converter, cos 0t and

90° phase lead b. Serial to parallel converter, sin 0t

and 900 phase lead c. Serial to parallel converter, sin 0t

and 90° phase lag d. Parallel to serial converter, sin 0t and

90° phase lag 47. Correctly sequence the blocks for an

integrating digital voltmeter from the list given below: 1. Integrator 2. Reference voltage 3. Converter 4. Control logic Select the correct sequence out of the following a. 1-2-4-3 b. 2-1-3-4 c. 1-2-3-4 d. 2-1-4-3

48. When a time varying signal has to be digitized using an ADO, it is necessary to use before digitization a/an a. Time division multiplexer b. Frequency division multiplexer c. Sample and hold circuit d. Instrumentation amplifier

49. Consider the following statements: 1. Flash AID converter is the fastest. 2. Minimum hardware is used in

implementing the Flash A/D converter. Which of the statements given above is/are correct? a. 1 only b. 2 only c. Both 1 and 2 d. Neither 1 nor 2

50. Copper has a much lower resistively than aluminum. SiO2 has a dielectric constant of 3.9 and Xerogel has a dielectric constant of 2.1. In order to reduce the interconnect delay in VLSI circuits, what should be the best combination of metal and dielectric layer? a. Copper with SiO2 b. Aluminum SiO2 c. Aluminium with Xerogel d. Copper with Xerogel

7 of 1451. Consider the following statements

concerning the ferromagnetic materials 1. There are easy and hard magnetization

directions in the ferromagnetic crystal. 2. Eddy current losses are smaller for

materials having low electrical conductivity values.

3. All ferromagnetic materials can be used at high frequencies.

Which of the statements given above are correct? a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

52. The E-field of a uniform plane wave propagating in a dielectric medium is given by

8 8, a 2cos 10 a sin 10 /3 3

x yz z

E t z t V m

What is the dielectric constant of the medium?

a. 1/ 3

b. 3

c. 3

d. 9 53. How long (in terms of wavelength) should

the short- circuited lossless line be so as to appear as an open circuit at the input terminals? a. / 4t b. / 2l c. / 3l d. l

54. Which one of the following is the capacity of standard telephone channel occupying the frequency range of 300 to 3400 Hz for an actual S/N ratio of 1023? a. 31000 bits per second b. 306900 bits per second c. 3478200 bits per second d. 17500 bits per second

55. Consider the following statements related to the ferroelectric materials: 1. Ferroelectric state occurs below a

particular temperature which is different for each material.

2. In the ferroelectric state dielectric constant is much larger than those of ordinary dielectric materials.

3. There is spontaneous polarization of the material when it is in the ferroelectric state.

Which of the statements given above are correct? a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

56. If N = number of atroms/m3 = Polaris ability

0 absolute permittivity of free space

Then the relative permitted of a gas subjected to a homogeneous electric field is

a. 0

1r

N

b. 2

0

1r

N

c. 0

r

N

d. 2

0

1r

N

57. Consider The Following Statements: The roots of the characteristic equation of a control system lead to its instability if they lie 1. On the imaginary axis of the s-plane 2. On the negative real axis of the S-plane 3. In the right-half of the S-plane Which of the above are correct?

58. A plane wave with an instantaneous expression for the electric field

10 20, a sin a sinx yE z t E t kz E t kz

is a. Linearly polarized b. Circularly polarized c. Elliptically polarized d. Horizontally polarized

59. Additional inductance in the local circuit of a phase- controlled connection feeding a separately-excited DC motor is used to a. Limit the possible ripple content b. Avoid the possibility of discontinuous

conduction c. Improve the line power factor

8 of 14d. Increase the rising angle limit during

inverter operation 60.

Which one of the following is the

minimum phase transfer function that corresponds to Bode magnitude plot shown in figure?

a. 1

2 1s

b. 2 1s

c. 1

11

2s

d. 1

12

s

61. Consider the LTI system with impulse response , 0,ath t e u t a which one

of the following gives the response to the signal atx t e u t ?

a. aty t e u t

b. aty t t e

c. aty t te u t

d. 2 aty t t e u t

62.

In the circuit shown in the figure, the ammeter (which gives deflection proportional to the current through it) reading is a. 0A b. 10A c. Oscillates between 0 and 10A d. Oscillates between – 10A and 10A

63. Consider the following statements In a transformer, an iron core is used to

1. Increase the useful flux 2. Educe the leakage flux 3. Reduce the useful flux Which of the above is/are correct? a. 2 only b. 1 and 2 c. 2 and 3 d. 3 only

64. A single-phase diode-bridge rectifier is connected to a load resistor of 50ohms. The source voltage is 200sin ,v t where 2 50 radians per second. The power dissipated in the load resistor is

a. 400

w

b. 2

3200W

c. 400W

d. 800

W

65. A single-phase AC voltage controller has input voltage of 300 V and runs at 50 Hz. The controller switch remains ON for four cycles and OFF for five cycles. The rms value of output voltage would be a. 133.33 V b. 166.67 V c. 200V d. 300V

66. If both the inputs to a half adder are 1, the sum and carry outputs are, respectively a. 0,0 b. 0,1 c. 1,0 d. 1,1

67. The number of non-trivial logic functions in a 2-variable logic family is a. 4 b. 10 c. 12 d. 16

68. a

9 of 14A sinusoidal oscillator is buit using an amplifier of real gain A, infinite input impedance and the feedback network

shown in the figure. If ,Z jX then 0Z is

equal to a. -2jX b. –jX c. iX d. 2jX

69. The only 16-bit long instruction in a machine code that uses immediate addressing mode in 8085 is a. LX1,HXXXX b. LDAXXXX c. LHLDXXXX d. LMPXXXX

70. Which of the following memory units needs periodic refreshing? a. ROM b. EPROM c. Static RAM d. Dynamic RAM

71. Two 3-phase alternators are synchronized so that their no-load voltages E1 and E2 are equal. If the excitation of machine 1 is now increased, then 1. A local circulating current I is set up. 2. Ic magnetizing in nature for machine 2. 3. Ic tends to reduce E11. 4. The terminal voltages does not change. Which of the statements given above are correct? a. 2 and 3 b. 1,2 and 4 c. 1, 3 and 4 d. 1, 2 and 3

72. A string insulator has 5 units. The voltage across the bottom-most is 25% of the total voltage. The string efficiency is a. 25% b. 50% c. 80% d. 75%

73. In load flow studies of a power system, a voltage control bus is specified by a. Real power and reactive power b. Real power and voltage magnitude c. Voltage and voltage phase angle d. Reactive power and voltage magnitude

74. Band-limited White Gaussian Noise means that the spectral density of the noise a. Is constant over a given band and has

any value elsewhere b. Is constant over a given band and has

zero value elsewhere c. Is zero over the given band and

constant elsewhere d. Varies over a given band and has zero

value elsewhere 75. In a communication system, the

probabilities of message occurrences are 1/8, 3/8, 1/8 and 3/8. The source entropy will be a. 1 .8 bits/message b. 2.8 bits/message c. 3.4 bits/message d. 5.6 bits/message

76. An average response rectifier type electronic AC voltmeter has a DC voltage of 10 V applied to it. The meter reading will be a. 7.1 V b. 10.0 V c. 11.1 V d. 22.2 V

77. Consider the following statements pertaining to strain gauges: 1. In metal strain gauge, the basic effect

is a change of resistance with strain. 2. Gauge factor of metal strain gauges is

larger than that of semiconductor strain gauges.

3. Gauge factor of semiconductor strain gauges varies with strain.

4. Metal strain gauges are insensitive to temperature.

Which of the statements given above is/are correct? a. 1 and 2 b. 2 only c. 1 and 3 d. 3 and 4

78. One example of combinational circuit is a. Adder b. Counter c. Shift register d. Flip-flop

79. A three input multiplexer will require a. A minimum of two select lines and one

output line

10 of 14b. One select line and one output line c. Three select lines and one output line d. Two select lines and two output lines

80. Ion-implantation is a superior process to diffusion because of which of the following reasons? 1. It is a high temperature process. 2. It results in precise control of depth

and profile. 3. Lattice damage due to high energy ion

beam can be annealed. Select the correct answer using the codes given below a. 1,2 and 3 b. 1 and 2 c. 2 and 3 d. 1 and 3

81. Consider the following process steps used in photolithography: 1. Alignment and Exposure 2. Pre-bake 3. Spinning 4. Development 5. Oxide etching 6. Post-bake 7. Photo resist stripping The correct sequence of these process steps is a. 3,2, 1, 5,6,4, 7 b. 2,3, 1,4, 5, 7, 6 c. 3,2, 1,4,6,5,7 d. 2,7, 1,4,3, 5,6

82. Which of the following properties does the SiO2 layer exhibit for use in IC fabrication? 1. It provides a protective conducting

layer on the silicon surface. 2. It provides surface passivation 3. It serves as an insulator on the silicon

surface. 4. It provides support for all IC

components to be fabricated over it. Select the correct answer using the codes given below: a. 2 and 3 b. 3 and 4 c. 1 and 4 d. 1 and 2

83. Match List I (Element of Mechanical System) with List H (Analogous Element

in Electrical Network) and select the correct answer: List I A. Mass B. Spring C. Damper D. Displacement List II 1. Inductance 2. Capacitance 3. Resistance 4. Charge 5. Current

A B C D a. 1 2 3 4 b. 4 3 5 1 c. 1 3 5 4 d. 4 2 3 1

84. Three blocks G1, G2 and G3 are connected in some fashion such that overall transfer

functions is 1 3 1 2

1 2

1

1

G G G G

G G

. The blocks

are connected in the following manner: a. G1, G2 with negative feedback and

combination parallel with G3 b. G1, G3 with negative feedback and G2

in parallel c. G1, G2 is cascade and combination in

parallel with G3 d. G1,G3 in cascade and combination in

parallel with G2 85. The unit impulse response of the system

described by

1 1y n y n X n X n

a. n

b. U(n) c. 1 d. 0

86. The 3-dB cutoff frequency of a first order low pass filter is c . If the input signal is

0.5 sin ct , the output will have a phase

shift of a. -45° b. -90° c. 45° d. 90°

87.

11 of 14

In the circuit shown in the figure, voltage v is given by

a. cc

dVV

dt

b. cV

c. cc

dvRCV

dt

d. cc

dvRC v

dt

88.

In this circuit shown, current through R is a. 0 b. 0.5A c. 2.5A d. 3.33A

89.

The peak current through the resistance in

the circuit shown is a. 18mA b. 12mA c. 8mA d. 4mA

90. The correct sequence of the following devices in the increasing order of turn-off times is a. MOSFET, IGBT, BJT, Thyristor b. IGBT, MOSFET, BJT,Jhyristor c. Thyristor, BJT, MOSFET, IGBT d. MOSFET, BJT, IGBT, Thyristor

91. An electric field in a charged medium with a time-varying magnetic field has

a. . 0; 0E E

b. . 0; 0E E

c. . 0; 0E E

d. . 0; 0E E

92. In HVDC transmission systems, filters are installed on a. AC side only b. DC side only c. Both on AC and DC sides d. Sending end only

93. The variation of near-zone electric field of a Hertzian dipole with radial distance R from the dipole is a. 1/R b. 1/R2 c. 1/R3 d. 1/R5

94. Assertion (A): The region of convergence (ROC) is defined as the set of Z for which the Z-transform converges. Reason (R): ROC cannot contain any poles of Z transform a. Both A and R are individually true and


R is not the correct explanation of A c. A is true but R is false d. A is false but R is true

95. Assertion (A): A wave guide does not support TEM wave. Reason (R): For TEM wave to exist on a transmission line, an axial conduction current must be supported a. Both A and R are individually true and



96. Assertion (A): In an intrinsic semiconductor, contribution to electrical conductivity by the electrons and the holes is the same. Reason (R): In an intrinsic semiconductor, the number of electrons in the conduction band is equal to the number of holes in the valence band

12 of 14a. Both A and R are individually true and



97. Assertion (A): It is relatively easier for polar water molecules to reorient themselves in the liquid state compared to the solid state. Reason (R): In the solid state, molecules are frozen and are not mobile at all. a. Both A and R are individually true and



98. Assertion (A): Many programmes prefer assembly level programming to machine language programming. Reason (R): It is possible to efficiently utilize the hardware of the computer in machine language programming. a. Both A and R are individually true and



99. Assertion (A): The different components of a composite video signal are needed consecutively and not simultaneously in TV receivers. Reason (R): The different components of a composite video signal are sent to the receiver on a frequency division basis. a. Both A and R are individually true and



100. Assertion (A): In a spectrum analyzer, the local oscillator may be automatically swept and the spectra indicated on a CRT for a high-frequency instrument. Reason (R): Spectrum analyzer contains intermediate frequency (IF) amplifier. a. Both A and R are individually true and

R is the correct explanation of A

b. Both A and R are individually true but R is not the correct explanation of A

c. A is true but R is false d. A is false but R is true

101. Assertion (A): Corona causes interference with neighboring communication circuits. Reason (R): Owing to distortion of wave form, predominantly third harmonics are introduced into the transmission line. a. Both A and R are individually true and



102. Assertion (A): A series-generator is used as a constant-current source by making use of its drooping part of the characteristic. Reason (R): For special applications a series DC generator is designed to have a low value of armature reaction which produces the drooping part of its external characteristic. a. Both A and R are individually true and



103. The power angle characteristic of machine-infinite bus system is

2sineP pu

It is operating at 30 . Which one of the following is the synchronizing power coefficient at the operating point? a. 1.0

b. 3

c. 2.0

d. 1/ 3

104. To produce frequency modulation through phase modulation, the modulating signal

me t is passed through block 1 and 2 as

shown in figure.

These two blocks are, respectively a. Phase modulator and differentiator b. Phase modulator and integrator c. Integrator and phase modulator

13 of 14d. Differentiator and phase modulator

105. A 3-phase cylindrical-rotor alternator is delivering rated power to a grid at its rated power factor. On account of some fault, steam supply to the turbine of the alternator is cut-off. The alternator would a. Stop b. Continue running as an alternator at

synchronous speed Ns and deliver active power to the grid

c. Continue running as a synchronous motor at Ns and deliver reactive power to the grid

d. Continue running as a synchronous motor at Ns and draw reactive power from the grid

106. A variable-reluctance stepping-motor has eight concentric coils on its eight-pole stator. Number of teeth on the rotor should preferably be equal to 1. Ti 2. Eight 3. Six 4. Four 5. Two Which of the above are correct? a. 1 and 3 b. 3 and 5 c. 2 and 3 d. 1, 2 and 4

107. Which methods can be used for the measurement of three phase power for an unbalanced load? 1. Three voltmeters 2. Two voltmeters and one ammeter 3. Two wattmeter’s 4. One wattmeter Select the correct answer using the codes given below: a. 1 only b. 3 only c. 1 and 3 d. Any one of 1,2,3 or 4

108. The resistance of a circuit is found by measuring the current flowing and the power fed into the circuit. The limiting error of power and current measurements are found to be ± 2% and ± 1 .25% respectively. Which one of the following is the limiting error in the measurement of resistance?

a. ± 0.45% b. ± 4.5% c. ± 2% d. ± 0.045%

109. The Central Processing Unit of a computer includes which of the following? a. Timing and control block, memory and

ports b. Timing and control block, ALU and

registers c. Timing and control block, ALU and

memory d. ALU, registers and ports

110. Machine instructions are written using which of the following? a. Bits 0 and 1 only b. Digits 0 to 9 only c. Digits 0 to 9 and the capital alphabets

A to Z only d. Digits 0 to 9, the capital alphabets A to

Z and certain special characters 111. Possible faults that may occur on a

transmission line are 1. 3-phase fault 2. L-L-G fault 3. L-L fault 4. L-G fault The decreasing order of severity of the faults from the stability point of view is: a. 1-2-3-4 b. 1-4-3-2 c. 1-3-2-4 d. 1-3-4-2

112. Consider the following statements The function of a condenser in a steam power plant is to 1. Condense the large volume of steam to

water to be used as boiler feed water. 2. Receive large volume of steam

exhausted from the steam turbine. 3. Maintain pressure below atmosphere

so that maximum heat energy can be extracted from steam.

Which of the statements given above are correct? a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 1, 2 and 3

14 of 14113. Match List I with List II and select the

correct answer: List I (Power Plant) A. Nuclear B. Diesel C. Gas turbine D. Hydro List II (Application) 1. Base load 2. Stand-by 3. Base load or peak load 4. Peak load

A B C D a. 1 3 4 2 b. 4 2 1 3 c. 4 3 1 2 d. 1 2 4 3

114. Match List I with List II and select the correct answer: List I (Protection Scheme) A. Differential protection B. Buchholz protection C. Earth fault protection D. Thermal protection List II (Type of Fault) 1. Phase to phase, and phase to ground 2. Phase to ground 3. Short circuit 4. inter-turn 5. Overloading

A B C D a. 1 4 2 5 b. 5 2 3 1 c. 1 2 3 5 d. 5 4 2 1

115. Which of the following methods could be used for I/O operation in an 8085 microprocessor? 1. Hand Shaking 2. Interrupting 3. Direct Memory Access Select the correct answer using the codes given below: a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1, 2 and 3

116. The devices given below are used by microprocessors and microcontrollers 1. RAM 2. EPROM

3. PORTS Which combination is available on-chip on a microcontroller? a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1,2 and 3

117. Phosphorus is being diffused into Silicon from an infinite source. Which of the following must be increased in order to increase the surface concentration? 1. Temperature of diffusion 2. Diffusion time 3. Concentration of the source Select the correct answer using the codes given below: a. 2 and 3 b. 1 and 2 c. 1 only d. 1 and 3

118. Consider the following statements: 1. A 16-bit shift register requires 16 flip-

flops. 2. A 16-bit ripple counter requires 4 flip-

flops. 3. A 16-bit synchronous counter requires

16 flip-flops. 4. A 16-bit ring counter requires 16 flip-

flops. Which of the statements given above are correct? a. 1,2 and 3 b. 1,2 and 4 c. 1, 3 and 4 d. 2, 3 and 4

119. When one of the suitable transducer form continuously monitoring the variation in thickness of paper? a. Strain gauge b. LVDT c. Diapharm d. Capacitance transducer

120. Which one of the following is the frequency band for satellite communication? a. 3 to 30 kHz b. 3 to 30 MHz c. 3 to 30 GHz d. 103 to 107 GHz

1 of 18

1.

If the input to the digital circuit consisting

of a cascade of 20 XOR gates is X, then the output Y is equal to

a. X’

b. X

c. 0

d. 1

2.

The minimal products-of-sums function described by the K-map given above is

a. A+C

b. A’+C’

c. AC

d. A’C’

3.

For the circuit show above, the Boolean expression for the output Y in terms of inputs P, Q, R and S is

a. P’+Q’+R’+S’

b. P+Q+R+S

c. (P’+Q’) (R’+s’)

d. (P+Q) (R+S)

4. If all the messages of a source have the same probability P, then the source entropy H (m) is given by

a. –log P

b. +log P

c. 1

P

P

d. 1 P

P

5. On the basis of equal carrier powers, the ratio of ‘signal-noise ratio of FM and signal-noise ratio of AM’ can be expressed as (assume that detector/ discriminator losses are zero)

a.

0 0

0 0

/3

/ t

S N FMm

S N AM

b.

0 0 2

0 0

/3

/ t

S N FMm

S N AM

c.

0 0 3

0 0

/4.5

/ t

S N FMm

S N AM

d.

0 0 3

0 0

/3

/ t

S N FMm

S N AM

6. To transmit N signals, each band limited to fm bny TDM, will require a minimum bandwidth of

a. mf Hz

b. 2 mf Hz

c. mNf Hz

d. 2 mNf Hz

7. In a DM system, the granular noise occurs when the modulating signal

a. Increases linearly

b. Increases exponentially

c. Remains constant

d. Decreases rapidly

8. Consider the following statements in connection with PCM system:

1. PCM is much better for noise immunity as it depends only on the pressure or absence of the pulses at any given time.

2. PCM requires a small bandwidth compared to analog systems.

3. PCM requires very complex encoding and quantizing circuitry.

C.S.E Pre-2005


2 of 184. PCM has all advantages of frequency

modulation when it comes to noise performance.

Which of the statement given above are correct:

a. 1, 2 and 4

b. 1, 3 and 4

c. 2, 3 and 4

d. 1, 2 and 3

9. The frequency spectrum of an amplitude-modulated signal contains

a. Carrier frequency only

b. Sideband frequencies only

c. Modulating frequency only

d. Carrier and sideband frequencies

10. An amplitude-modulated analog waveform has a maximum amplitude Amax and a minimum amplitude Amin (a positive value), then the modulation index is given by

a. min

max

A

A

b. min

max min

2A

A A

c. max min

max min

A A

A A

d.

max min

max min2

A A

A A

11. In connection with properties of the Fourier transform, match List-I (Function of Time) with List— II (Spectral Density Function) and select the correct answer using the code given below the Lists:

List I

List II

A B C D

a. 1 3 2 4

b. 2 1 4 3

c. 1 3 4 2

d. 2 1 3 4

12.

Fourier transform of the gate function as shown above is

1 / 2 / 2

0 Otherwise

f t for t

where is the width of the gate function

the value of F is

3 of 18

a. sin

b. sin 2

2

c.

/ 2

/ 2

sib

d.

sin / 2

.2 / 2

13.

The circuit shown in above figure uses as

ideal Op-Amp working with +5V and -5V power supplies. The output voltage V0 is equal to

a. +5V

b. +1V

c. –1V

d. –5V

14.

The circuit given above is

a. Peak detector

b. Schmitt trigger

c. Buffer amplifier

d. Unity gain amplifier

15. Match List —I (Scheme of Feedback) with List—II (Performance Measure) and select the correct answer using the code given below the Lists:

List I

A. Current series

B. Current Shunt

C. Voltage series

D. Voltage shunt

List II

1. Input impedance increases, output impedance decreases

2. Input impedance decreases, output impedance decreases

3. Input impedance increases, output impedance increases

4. Input impedance decreases, output impedance increases

A B C D

a. 3 4 2 1

b. 2 1 3 4

c. 3 4 1 2

d. 2 4 3 1

16.

The forward resistance of the diode shown

in above. figure is and the remaining parameters are same as those of an ideal diode. The d.c. component of the source current is

a. 50

mV

b. 50 2

mV

c. 100 2

mV

d. 2

50mV

17. The per unit impedance of a circuit element is 015. If the base kV and base MVA are halved, then what will be the new value of the per unit impedance of the circuit element?

a. 0.075

b. 0.15

c. 0.30

d. 0.60

18.

4 of 18A bundled conductor has 3 conductors equaliterally spaced as shown above. Ds is the GMR of the individual conducto4r. what is the GMR of the bundled conductor?

a. 1/2

sD d

b. 1/3D d

c. 1/32sD d

d. 2sD d

19. Which one of the following line, if the impedance of the line is 0.01+j0.15 per unit when the load current is 1.0 p.u. at 0.8 lag power factor and the receiving end voltage Vr=1.0 p.u. what is the regulation of the line?

a. 0.8%

b. 0.9%

c. 9.8%

d. 1%

20. Which one of the4 following yields the value of sag of conductors between two poles? (W is weight per unit length of conductor in N/m, L is the distance between two poles in meter, T is the tension in conductor in N)

a. 2 /16WL T

b. 2 / 8WL T

c. 2 / 2WL T

d. 2 /WL T

21. For nominal -representation of the transmission line , the ABCD parameters are related to Z and Y of the line, such that C parameter is given by

a. 1 1/ 2C YZ

b. C=Z

c. 1 1/ 2C Z YZ

d. 1 1/ 4C Z YZ

22. Which one of the following statements is correct:

In a load-duration curve for an integrated power system the uppermost crest represents the energy contributed by

a. Base power station

b. Major thermal station

c. Peaking hydro or gas turbine stations

d. Non-conventional power stations

23. Consider the following statements for a signal-phase hysterias motor:

1. Torque is constant form standstill up to synchronous speed Ns.

2. Rotor is provided with narrow slots embedded with bars.

3. Torque at starting is some what more than that at synchronous speed Ns.

4. As the name suggests, only hysterias torque is produced form zero speed right up to N3.

5. Rotor material possesses very wide hysteretic loop.

Which of the statements given above are correct?

a. 1,2 and 5

b. 3 and 5

c. 1 and 4

d. 2,3 and 5

24. The field current of a synchronous motor is increased while its load is constant. How will its power angle and power factor change?

a. Power angle decreases and power factor improves

b. Power angle remains same throughout but power factor improves

c. Power angle increases while its power factor gradually decreases

d. Power angle and power factor both increase

25. The alternators (M1 and M2) have been properly synchronized and connected in parallel to a common bus bar. If there is no load on the bus bar and the field excitation of the second alternator (M2) is increased gradually by a small amount from its normal excitation for which the induced e.m.f.’s E1 and E2 of the two machines are equal, the armature reaction due to the circulating armature current would be

a. Magnetizing for M1 but demagnetizing for M2

b. Demagnetizing for M1, but magnetizing for M2

c. Magnetizing for both M1 and M2

d. Demagnetizing for both M1 and M2

5 of 1826. Match List I (Type of signal-phase

induction Motor) with List II (Torque-speed characteristic) and select the correct answer using the code given below the lists:

List I

A. Capacitor-run motor

B. Capacitor-start and run motor

C. Shaded-pole motor

D. Resistor-split phase motor

List II

A B C D

a. 2 1 3 4

b. 2 3 1 4

c. 3 4 2 1

d. 3 4 1 2

27. In a 3phase induction motor, if Pg is power transferred across the air gap and S is the slip, then the ratio of motor copper loss to the mechanical power developed is given by

a. 1

s

s

b. S

c. 1

S

d. 1 S

S

28. The prevent the shifting of the magnetic natural axis, caused by the armature

reaction in a d.c.; machine, the most effective method to neutralize the armature flux is to

a. Shift the ‘brush-axis’

b. Provide high-reluctance main pole tips

c. Cut horizontal slots in the main poles

d. Place compensating windings of the main-pole faces

29.

A single-phase two-winding transformer

shown above in Fig. 1, is connected an autotransformer shown in Fig, 2 if the connections of the 100V winding are reversed as shown in Fig.3, what is the value of the voltage V1 required to be applied across terminals X2 and H2 to obtain the same 400 V output?

a. 500 V

b. 400 V

c. 300 V

d. 100 V

30. Two transformers with identical voltage ratings are working in parallel to supply a common load. The percentage impedance of one transformer is higher compared to that of the other. The load sharing between the two transformers will

a. Be proportionate to their perce3ntage impedances

b. Be independent of their percentage impedances

c. Be inversely proportional to their respective impedances

d. Depend on the resistance to leakage reactance ratio of each transformer

31. Consider a system having forward path and feedback path transfer functions as 1/6 [s(s+0.8)] and (1+2s) respectively. Which is the characteristic polynomial of the system?

a. 2 0.8 16s s

b. 2 2.8 16s s

6 of 18c. 2 32.8 16s s

d. 2 32 16s s

32. Which of the following correct?

The feedback affects the control system in the following ways:

1. Increases accuracy but reduces sensitivity of gain top variation in system parameters.

2. Increases bandwidth and reduces the effect of nonlinearity.

3. Increases tendency towards oscillation or leads even to instability.

Select the correct answer using the code given below:

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1,2 and 3

33. the transfer function

1

C s A s

R s B s

Is the simplification of which one of the following diagrams?

(a)

34. Which one of the following figure

represents the magnitude plot of the

transfer function 1

2

jeH

?

35.

The Laplace transform of V(t) shown in he above figure is

a. 22

1 11 s se e

s s

b. 22

1 11 s se e

s s

c. 22

1 11 s se e

s s

d. 22

1 11 s se e

s s

36. If f(t) and F(s) form the Lap lace transform pair, then what is the Lap lace transform of 0/f t t ?

a. 0 0t F t s

b. 00

1F t s

t

c. 00

1t F s

t

d. 0 0

1 1F s

t t

37. What is the steady-state response of a

system 2

1

3 2

R s

R s s s

When unit step input is applied?

a. 0.5

b. 1.0

c. 1.5

d. 0

7 of 1838. The forward voltage transfer function of a

two-port network is 2 2

s

s

What will be the output voltage if the input voltage is t ?

a. 2 sin / 4t

b. cos sint t

c. cos t

d. 2 sin / 4t

39. Which of the following characteristics of the system are defined by y(t) = x(t) cos (100 t )?

1. It is linear.

2. It is time invariant.

3. It is causal.

4. It is a stable

5. It is memory less.


a. 1,2,3 and 4

b. 2,3 and 5

c. 4 and 5

d. 1,2,3, 4 and 5

40. Match List I (Pole Location) with List II (Time response due to initial condition) and select the correct answer using the code given below the lists:

List I (Pole Location)

List II

A B C D

a. 2 1 4 3

b. 1 2 4 3

c. 2 3 1 4

d. 1 3 2 4

41.

Which one of the following gives the h-parameter matrix for the network shown above?

a.

1be

e d

cb b

r r

r r

8 of 18

b. 1b e cb

bce d

r r

r r

c. 1b e be

cbe d

r r

r r

d. 1bc cb

b ee d

r rr r

42.

For the a.c. circuit given above, if the

power dissipated by the 5 resistor is 10 W, then what is the power factor of the circuit?

a. 0.9 lagging

b. 0.6 lagging

c. 0.9 leading

d. 0.6 leading

43. A 2-terminal network is one of the R-L-C elements. The elements is connected to an a.c. supply. The current through the element is. I when a capacitor is instated in series between the source and the element, the current through the element becomes element, the current through the element because

a. Is a resistor is an inductor

b. Is a capacitor

c. Is a capacitor

d. Cannot be a single element

44.

For The Above Circuit, If The Current I = 3 A and 1.5 A for RL = and 2 respectively, then what is the value of I for RL = 1 ?

a. 0.5 A

b. 1.0A

c. 2.0A

d. 3.0A

45.

For the reduced incidence matrix given above, which is the set of branches forming a tree?

a. 1,2,3

b. 2,4,6

c. 2,3,5

d. 1,4,6

46.

What is the value of the current I in the

circuit shown above?

a. 1 A

b. –3A

c. –6A

d. 9A

47. The 4-bit, 2’s complement representation of a decimal number is 1000. What is the number?

a. +8

b. 0

c. –7

d. –8

48.

The output f of the 4-to-1 MUX shown in

the above figure is

a. 'xy x

b. x y

9 of 18c. ' 'x y

d. 'xy x

49.

The frequency of the clock single applied

to the rising edge triggered D flip-flop shown in the figure given above is 10 kHz. What is the frequency of the signal available at Q?

a. 20 kHz

b. 10 kHz

c. 5 kHz

d. 2.5 kHz

50.

The circuit in the figure given above has two CMOS NOR gates. This circuit functions as a/an

a. Flip-flop

b. Monostable multivibrator

c. Schmitt trigger

d. Astable multivibrator

51. What is number of the comparators-type ADC?

a. 2

b. 3

c. 7

d. 8

52. The available multiple access and broadcasting systems are

1. SPADE

2. TDMA

3. FDMA

4. CDMA

5. SDMA

Which of the above are employed for satellite communications?

a. 1,2 and 3

b. 2,3 and 4

c. 1 and 4

d. 1,2,3,4 and 5

53. If the maximum Radar range is to be doubled, the power of the Rader transmitter is to be increased (keeping all other parameters intact)

a. Two times

b. Four times

c. Eight times

d. Sixteen times

54. Which one of the following statements is correct?

If a periodic signal exhibits half-wave symmetry, then in the trigonometric Fourier series

a. All the sine terms vanish

b. All the cosine terms vanish

c. The constant term vanish

d. All the even harmonics vanish

55. How are vector processors and array processors classified?

a. Single-instruction, Single-data (SISD) computers

b. Single-instruction, Multiple data (SIMD) computers

c. Multiple-instruction, Single data (MISD) computers

d. Multiple-instruction, Multiple data (MIMD) computers

56. What is/are the disadvantage(s) of Gauss-Seidel method over Newton’s method in load-flow programmes?

a. More iteration

b. More memory requirement and less accuracy

c. Less iterations but more memory

d. More accuracy and more memory

57. Match List I with List II and select the correct answer using the code given below the lists:

List I

A. Buchholz relay

B. Mho relay

C. Impedance relay

D. Reactance relay

List II

1. Long lines

10 of 182. Short lines

3. Medium lines

4. Transformers

A B C D

a. 4 1 3 2

b. 3 2 1 4

c. 4 3 2 1

d. 3 4 2 1

58. If the fault current is 2000 A, the really setting is 50% and CT ratio is 400:5, then what is the plug setting multiplier?

a. 25

b. 15

c. 50

d. 10

59. In a static over-current relay, how are inverse time characteristic obtained?

a. By using a transistor amplifier

b. By using an integrating circuit

c. By using a transistor switch

d. By using a differentiating’ circuit

60. Satisfactory turn-off of a thuristor takes place if the reverse bias period of the device, after its current has beco9me zero, is

a. Greater than its turn-off time

b. Less than its turns-off time

c. Greater than the circuit time-constant

d. Less than the circuit time-constant

61. a

A MOSFEI’ rated for 20 A, carries a periodic current as shown in the above figure. The on-state resistance of the MOSFE is 0.2 ohm. What is the average on-state power loss of device per cycle?

a. 20 W

b. 15W

c. 10W

d. 5W

62.

A half-wave thyristor-converter supplies a purely inductive load as shown in the above figure. If the triggering angle of the thyristor is 120°, then what is its extinction angle?

a. 120°

b. 180°

c. 200°

d. 240°

63. Match List-I with List-H and select the correct answer using the code given below the Lists:

List I (Converter)

A. Fully controlled converter

B. Half-controlled converter

C. 3-phase a.c. voltage controller

D. Cycloconvertyer

List II (Application)

1. Improved time power factor

2. Soft starter for a.c. motor

3. Smooth low speed reversible high power a.c. drives

4. Synchronous motor control

A B C D

a. 3 1 2 4

b. 2 4 5 1

c. 3 4 2 1

d. 2 1 5 4

64. Which of the following are the advantages of free wheeling of load current in phase-controlled converters?

1. It is reduces reactive power demand of the converter.

2. It improves the displacement factor.

3. It improves distortion factor

4. It requires larger inductance to provide contagious conduction.


a. 1,2,3 and 4

b. 1,2 and 3

11 of 18c. 1 and 4

d. 2,3 and 4

65. Which of the following are the functions of feedbacks diodes in a McMurray inverter?

1. To free-wheel the load current.

2. To provide required reverse bias across the outgoing thryristor.

3. To provide the return path for the reactive current of load.

4. To provide a path for the excess of communication current above the load current.

Select the current answer using the code given below:

a. 2,3 and 4

b. 2 and 4

c. 1,2 and 3

d. 3 and 4

66. A 3-phase induction motor o-perate3s at constant slip frequency while the stator frequency is varied from 0 to rated value. Which one of the following is correct?

The torque developed by the motor is

a. Proportional to speed

b. Proportional to speed

c. Proportional to square of speed

d. Inversely proportional to speed

67. Assertion (A): A signal has to be sampled at twice the maximum frequency of the signal to recover it from the sampled signal.

Reason (R): Sampling is to be done at Nyquist rate to avoid aliasing.

a. Both A and R are individually true and R is the correct explanation of A.

b. Both A and R are individually true but R is not the correct explanation of A.

c. A is true but R is false.

d. A is false but R is true.

68. Assertion (A): For a good degree of relative stability; a control system should have a phase margin of about 400 and a gain margin of 05.

Reason (R): A large gain margin or a large phase margin corresponds to a highly oscillatory system, and a very small gain margin or a phase margin approaching 00 indicates a very stable but sluggish system.





69. Assertion (A): SiCl4 is added to Cl2 in order to dry etch aluminum anisotropic ally.

Reason (R): Cl2 etches aluminum while SiCl4 etches native aluminum oxide and also provides anisotropy by forming sidewall inhibitors.





70. Assertion (A): In discrete as well as IC device fabrication, wet oxidation of Si into its natural oxide is preferred.

Reason (R): The rate of growth of wet oxidation is lower than that for dry oxidation, hence a better quality oxide can be grown.





71. Assertion (A): Differential amplifier is biased with a current source for high CMRR.

Reason (R): Differential amplifier will have higher gain for common mode signals.





72. Assertion (A): A self-controlled synchronous motor fed from a CSI, need not have damper windings.

12 of 18Reason (R): Damper windings are responsible for sub transient reactance in synchronous motors.





73. Assertion (A): Given a unity feedback

system with 4

KG s

s s

the value of

K a damping ratio of 0.5 is

a. 1

b. 16

c. 4

d. 2

74. Match List I with List II and select the correct answer using the code given below the lists:

List I (Characteristic Equation)

A. 2 8 15 0s s

B. 2 24 225 0s s

C. 2 20.25 0s

D. 2 20 100 0s s

List II (Nature of unit step Response)

1. Un damped

2. Un dreamed

3. Critically damped

4. Over damped

A B C D

a. 1 3 2 4

b. 4 3 1 2

c. 1 4 3 2

d. 4 2 1 3

75. Given that matrix

0 1 0

0 0 1

6 11 6

A

What are the eigen values of A?

a. –1,–2,–3

b. –1,2,–3

c. 0,0,–6

d. –6, –11,–6

76. Consider the following statements based on gain margin and phase of a system:

1. for stable systems, the gain cross-over frequency is less than phase cross-over frequency

2. for unstable systems, the gain cross-over frequency is greater than phase cross-over frequency

3. For marginally stable systems, the gain cross-over frequency is equal to phase cross-over frequency.

Which of statements given above area correct?

a. 1 and 2

b. 2 and 3

c. 1 and 3

d. 1,2 and 3

77. Which one of the following represents the transfer function of a phase-lag controller?

a. 1

, 11

aTsa

Ts

b. 1

, 11

aTsa

Ts

c. 1

, 11

aTsa

Ts

d. 1

, 11

aTsa

Ts

78. In order to reduce steady-state error of a control system, which one of the following control schemes will be employed?

a. Cascade PD

b. Cascade PI

c. Rate feed back

d. Integral feedback

79.

The resistance measured between the two ends of the toroid shown in the above figure is R. what would be the resistance if both a and a b are doubled?

a. 2R

b. R

c. R/2

13 of 18d. R/4

80.

A square loop and an infinitely long

conductor, each carries a current I as shown in the girue given above.

What is the force on the loop?

a. 2

0

4

I

away from the conductor

b. 2

024

I

towards the conductor

c. 2

0

4

I

log, 2 away from the conductor

d. 2

0

4

I

loge 2 towards the conductor

81. A metallic sphere with charge – Q is placed inside a hollow conducting sphere with radius R carrying a charge +Q. potential at a given point outside the hollow sphere

a. Depends on the positions of the metallic sphere

b. Is solely deviled by the charge on the outer sphere

c. Is always zero whatever may be the position of the inner sphere

d. Is zero only when both spheres are concentric

82.

The magnetic vector potential at the point

P due to the current loop C shown in the above figure is in the direction of

a. xa

b. ya

c. za

d. 2

x ya a


a. The normal electric field components have the same value

b. The tangential magnetic field components are continuous

c. The electromagnetic wave is reflected back according to Snell’s law

d. The electromagnetic wave is diffracted

84.

For the current I decreasing in the indicated direction, the e.m.f. in the two loops A and B shown in the figure above, is in the direction

a. Clockwise in A and anticlockwise in B

b. Anticlockwise in A and clockwise in B

c. Clockwise in both A and B

d. Anticlockwise in both A and B

85.

86. A structure consisting of two loss-less

lines, each / 4 long and terminated in a resistance R, is shown in the figure given above. The lines have characteristic impedances of 2Z0 and Z0 respectively as shown. What is the impedance measured at the end XX?

a. R

b. 4R

c. 20 /Z R

d. 204 /Z R

87. Match ListI (Expression) with List II (Coefficient) and select the correct answer using the code given below the Lists:

List I (Expression)

A. 0

0

L

L

Z Z

Z Z

14 of 18

B. 0

0

L

L

Z Z

Z Z

C. 0

2 L

L

Z

Z Z

D. 0

0

2

L

Z

Z Z

List II (Coefficient)

1. Reflection coefficient for voltage

2. Transmission coefficient for Voltage

3. Reflection coefficient for current

4. Transmission coefficient for current

5. Standing-wave ratio

A B C D

a. 1 2 5 4

b. 4 3 2 1

c. 1 3 2 4

d. 4 2 5 1

88. In a rectangular waveguide, what is the ratio of eave impedance for TM mode to wave impedance for TE mode . . /IM TEi e X Z ?

a. 1

b. 2

1

1 /ef f

c. 21 /ef f

d. 21 /ef f

89. Match List I (Transfer characteristics of clipper Circuit/Rectifier) with List—Il (Type of Clipper! Rectifier) and select the correct answer using the code given below the Lists:

List I (Transfer characteristics of clipper circuit/rectifier)

List II (Type of clipper/Rectifier)

1. Doubled-ended clipper

2. Positive clipper

3. Negative clipper

4. Full-wave positive rectifier and not a clipper

A B C D

a. 1 2 3 4

b. 2 3 4 1

c. 1 2 4 3

d. 2 3 1 4

90. Consider the following circuits:

Which of the following circuits will yield

the following input-output characteristics for the clipper?

0 1 i

i

V V for V V

V for V V


a. 1 only

b. 2 only

c. 1 and 3

d. 1,2 and 3


A multiple-zone process is used for refining Si from impurities having segregation coefficient K.cl. The ingot is held vertically and the zone is moved from bottom to top of the ingot. After each run

15 of 181. The top end of the ingot contains

maximum impurities and is to be cut thrown before the next run.

2. The bottom end of the ingot contains maximum impurities and is to be cut and thrown before the next run.

3. There is no need of cutting the bottom end before the next run as it contains minimum impurities.

Which of the statements given above is/are correct?

a. 1 only

b. 2 only

c. 2 and 3

d. 1 and 3

92. Which of the following statements are correct?

1. Molecular Beam Epitaxy (MBE) is a physical evaporation process while Vapour Phase Epitascy (VPE) involves chemical reaction.

2. In-situ etching of silicon is possible only in MBE but not in VPE system.

3. MBE of silicon is carried out at a. lower temperature compared to VPE.

4. The growth rate of the exit axial film can be accurately controlled during BME than during VPE.


a. 1 and 2

b. 3 and 4

c. 1, 3 and 4

d. 2, 3 and 4


Rapid Thermal Annealing (RTA) is preferred over conventional furnace annealing after ion-implantation because

1. RTA does not cause any change in the doping profile.

2. Thermal budget is lower if RTA is used.

3. RTA is carried out at lower temperature.

Which of the statements given above is/are correct?

a. 1, 2 and 3

b. 1 and 2

c. 1 only

d. 2 only


CZ method of crystal pulling is a popular technique for converting bulk material to single crystal because

1. It requires a seed of single crystal to initiate the growth.

2. The seed crystal should be pure and defect free for high quality growth.

3. Intentionally doped single crystals cannot be obtained by this technique.

Which of the statements given above are correct?

a. 1,2 and 3

b. 1 and 2

c. 2 and 3

d. 1 and 3

95. What is the correct sequence of the following steps during isolation by LOCOS technique?

1. Si etching

2. Growth of thin pad oxide

3. deposition and patterning of silicon nitride

4. growth of SiO2

Select the correct answer using the code given below

a. 1-3-4-2

b. 2-3-1-4

c. 4-2-1-3

d. 3-1-4-2

96. Consider the following statements about ferrites:

1. Ferrites have high resistively.

2. Ferrites have low eddy current losses.

3. Ferrites are used as core materials in high frequency (MHz) transformers.

Which one of the statements given above are correct?

a. 1,2 and 3

b. 1 and 2

c. 1 and 3

d. 2 and 3

97. A necessary but not a sufficient condition for a crystal to show Ferro-electricity is

a. Absence of centre of symmetry

b. Presence of centre of symmetry

16 of 18c. Presence of both translational and

rational symmetry

d. Absence of both translational and rational symmetry

98. In a dielectric material there are four contributions to the total polarization. Out of these only one is dependent on temperature and this contribution is

a. Electronic polarization

b. Space-charge polarization

c. Ionic polarization

d. Orientation polarization

99. If m = permanent dipole moment, k=Boltzmann constant and T = absolute temperature, then orientation Polaris ability is equal to

a. 3

m

kT

b. 2

3

m

kT

c. 3kTm

d. 23kTm

100. Which one of the following statements is correct? Copper and silicon are forming a junction; at thermal equilibrium

a. The Fermi levels in the two materials are at the same energy level irrespective of the number of free electrons in copper and silicon

b. The Fermi level of copper is at a higher energy level compared to that of silicon as copper has more free electrons

c. The Fermi level of silicon is at a higher energy level compared to that of copper as silicon has more free electrons

d. Copper and silicon, being in thermal equilibrium, will have the same specific heat and Fermi levels have no relation to thermal equilibrium

101. The life time of the minority carriers in p-n junction solar cells is determined by

a. Hall effect experiment

b. Haynes-Shockley experiment

c. Electron beam induced current decay experiment

d. Secondary Ion Mass Spectros-copy experiment

102. For a crystal, which one of the following statements is correct?

a. The total number of possible wave functions in any energy band is equal to the number of unit cells

b. The total number of possible wave functions in any energy band is equal to twice the number of unit cells according to Pauli principle

c. The total number of possible wave functions in any energy band is equal to the total number of free electrons in the band

d. The number of possible wave functions in any energy band is independent of the number of unit cells

103.

The figure given above shows a two winding core- type transformer. The instantaneous directions of the primary current I1, the mutual flux m and the

primary leakage flux 1 are as indicated

in the figure; the corresponding directions, at the same instant, of the secondary current I2 and the secondary leakage flux 2 would be

a. 2 2, ; andI a to b c to d

b. 2 2, to ; and to I b a c d

c. 2 2, to ; and to I a b d c

d. 2 2, to ; and to I b a d c

104. While measuring the value of distributed capacitance by Q-meter, the resonances were obtained with values of tuning capacitor as C1 and C2 for the frequencies adjusted to f1 and 2f1 respectively. What is the value of the distributed capacitance?

a. 1 22

2

C C

b. 1 24

2

C C

17 of 18

c. 1 22

3

C C

d. 1 24

3

C C

105.

In the figure shown above A1, A2 and A3 are ideal ammeters. If A2 and A3 read 4A and 5A respectively what is the reading of A1?

a. 1A

b. 3A

c. 9A

d. Cannot be calculated without the values of R and C

106. Wagjner’s earth devices are used for a.c. bridge circuits for

a. Eliminating the effect of earth capacitances

b. Eliminating the effect of earth capacitance

c. Eliminating the effect of stray electrostatic fields

d. Shielding the bridge elements

107. While testing a coil having a resistance of 1 , resonance occurred when the oscillator frequency was 10 MHz and the

variable capacitor was set at 500

2

pf.

What is the effective value of Q of the coil?

a. 200

b. 254

c. 314

d. 542

108.

The above diagram shows De sauty method to measure the unknown capacitance (Cx).CX is given by

a. 2

1x

RC C

R

b. 2

1x

RC C

R

c. 1

2x

RC C

R

d. 1

2

22

x

RC C

R

109. A resistance is measured by the voltmeter-ammeter method. The voltmeter reading is 50V on 100V scale and ammeter reading is 50 mA scale. If both the meters are guaranteed for accuracy within 2% of full scale, what is the limit within which resistance can be measured?

a. 10

b. 20

c. 40

d. 80

110. A resistance of 110 2 is specified using significant figures as indicated below:

1. 110

2. 110.0

3. 0.000110M

For the above three indications, which one of the following statements is correct?

a. 1 represents greater precision than 2 and 3

b. 2 represents greater precision but 1 and 3 represent same precision

c. 2 and 3 represent same precision

d. 3 is more precise than 1 and 2

111. A 35 V d.c. supply is connected across a combined resistance of 600 ) and an unknown resistance of R in series. If a voltmeter having a resistance of 1.2 k is connected across 600 resistor and reads 5V, then what is the value of the resistance R?

a. 120

b. 500

c. 1.7k

d. 2.4k

112. Consider the following components:

18 of 181. SRAM

2. EPROM

3. USART

4. PORT

Which of the above components are not found on-chip in a microprocessor but may be found on-chip in a microcontroller?

a. l,2,3 and 4

b. l,2 and 3

c. 1, 2 and 4

d. 3 and 4

113. In memory-mapped I/O scheme, all data transfer instructions of 8085 microprocessor can be used only for

a. Memory devices

b. I/O devices

c. Ports

d. Memory and I/O devices

114. Assembler directives are required

a. Only in hand assembling

b. Only in machine assembling

c. In hand assembling as well as machine assembling

d. Only when there is an operating system

115. A microprocessor using a 3 MHz - clock has three ‘T’ states in each machine cycle. If an instruction cycle needs 4 machine cycles, how much time will be taken to complete the execution of this instruction?

a. 333 ns

b. 1333 ns

c. 1 s

d. 4 s

116. How many general purpose 8-bit registers are there in 8085 microprocessor?

a. 3

b. 6

c. 9

d. 12

117. Consider the following:

1. Small capacity

2. Fast memory access

3. Needs refreshing

4. Very costly

The essential characteristics of a Cache memory include

a. 1, 2, 3 and 4

b. 1, 2 and 3

c. 1, 2 and 4

d. 3 and 4

118. An instruction cycle is the tune in which, a hardwired controller completes four functions. What is the correct sequence of these functions?

a. Fetch update - decode – execute

b. Fetch - decode - update – execute

c. Decode - execute - fetch – update

d. Execute - decode - fetch - update

119. Consider the following four components found in the ALU of a computer:

1. XOR gates

2. Half-adder

3. Full subtract or

4. Shifter

Which of the above components are combinational circuits?

a. 1, 2, 3 and 4

b. 1, 2 and 3

c. 1 and 2

d. 3 and 4

120. Which of the following addressing modes imply that the operand is stored separately in the main memory?

1. Indirect

2. Immediate

3. Indexed


a. 1, 2 and 3

b. 1 and 2

c. 2 and 3

d. 1 and 3

1 of 14

1. Match List-I with List-II and select the

correct answer using the code given below the lists: List I (Character) A. Colon (:) B. Blank ( ) C. Comma (,) D. Semicolon (;) List II (Interpretation) 1. Separates operation and operand fields. 2. Separates operands 3. Beginning of comment field 4. End of label field

A B C D a. 2 3 4 1 b. 4 1 2 3 c. 2 1 4 3 d. 4 3 2 1

2. In a memory map the lowest address of an 8 k byte RAM is 1000 H. what is the highest address? a. 8192 H b. 2 F F F H c. 7 F F F H d. 3000 H

3. Which one of the following statements is correct? In 8085 p , the READY signal is useful when the CPU communicates with a. A PPI chip b. A DMA controller chip c. A slow peripheral chip d. A fast peripheral chip

4. A current of

2 2 sin 314 30 2 2 cos 952 45t t

is measured with a thermocouple type, 5 A full scale meter. What is the meter reading? a. 2A b. 3A c. 5A

d. 2 3 2 A


In an energy meter, the braking device is provided to produce braking torque so that the a. Energy meter can be brought to a

standstill b. Meter creeping be checked c. Moving system of the instrument (disc)

rotates at a speed for a particular rate of energy consumption at 4. any time

d. Shunt field flux lags behind voltage by exactly 90°

6. Three voltmeter method used for power factor measurement gave the following readings V1 = 200 Volts across an inductive load, V2 = 180 Volts across a non-inductive resistor, and V3 = 300 Volts across the two in series. What is the power factor of the inductive load? a. 0.244 b. 0.30 c. 0.75 d. 080

7. Which one of the following is the correct statement? Chopper stabilized d.c. amplifier type electronic voltmeter overcomes the effect of a. Amplifier CMRR b. Amplifier drift c. Amplifier sensitivity d. Electromagnetic interference

8. Which one of the following is the correct statement? In an LVDT, the two secondary voltages a. Are independent of the core position b. Vary unequally depending on the core

position c. Vary equally depending on the core

position d. Are always in phase quadrate

9. A strain gauge has a nominal resistance of 500 2. When a strain of 2 × 10-4 is applied, the change in resistance is 0.5 . What is the gauge factor for the strain gauge? a. 1

C.S.E Pre-2006


2 of 14b. 2.5 c. 5 d. 10

10. Which of the following is/are essential sub-system (s) of a data acquisition system? 1. ADC 2. DAC 3. RAM 4. Processor 5. Network Card Select the correct answer using the codes given below a. 1, 2, 3 and 4 b. 3 and 5 c. 4 only d. 1, 3 and 4, only

11. A 3-phase fully controlled a.c. to d.c. converter feeds a ripple free average current of 200 A to a d.c. load. What is the rms value of current carried by each thyristor? a. 200 A

b. 200 2

3A

c. 200

3

d. 200

3A

12. A single phase diode bridge rectifier with finite value of source inductance feeds on R-L load. The load current can be assumed to be ripple free. What is the source current wave form? a. Sinusoidal b. Triangular c. Square wave d. Nearly trapezoidal

13. Which one of the following is the correct statement? In a d.c. chopper the free wheeling diode across the load a. Improves the efficiency of power

conversion of the chopper b. Causes high voltage across the main

thyristor c. Causes high voltage across the

auxiliary thyristor d. Avoids high voltage when the main

thyristor is turned off

14. Which one of the following statements is correct? The peak inverse voltage rating of a thyristor in a McMurray inverter a. Can be as small as the forward voltage

drop of diode, i.e., equal to 1 to 1.5 V b. Should be the same as forward break

over voltage c. Should be much greater than the

forward break over voltage. d. Is a very significant factor in the

design of the inverter. 15.

For a random variable ‘x’ following the

probability density function P(s) shown in the figure given above, what are the mean and variance, respectively? a. ½ and 2/3 b. 1 and 4/3 c. 1 and 2/3 d. 2 and 4/3

16. If a signal f(t) has an energy ‘E what is the energy of the signal f(2t) ? a. E (b) b. E/2 c. 2 E d. 4 E

17. To transmit N signals, each band limited to ‘f’ Hz, using PCM and time division multiplexing over a channel, what is the minimum bandwidth required for distortion less transmission? a. f Hz b. NfHz c. f/N Hz d. 2 N f Hz

18. The local oscillator in a BPSK signal detector has a fixed phase error of 30°. This phase error deteriorates the SNR at the output by what factor? a. 0.87 b. 0.75 c. 0.5 d. 0.25

19. In a PCM system with uniform quantization, increasing the number of bits

3 of 14from 8 to 9 will reduce the quantization noise power by which factor? a. 9 b. 8 c. 4 d. 2

20. If the antenna diameter in a radar system is increased by a factor of 2, the maximum range will be increased by what factor a. 2 b. 4 c. 8 d. 16

21. Given 224) 13)r r .

What is the value of the radix r? a. 10 b. 8 c. 6 d. 5

22. Which one of the following statements is correct? If a computer has a “uni-bus” organization it means that the computer has only one a. Data bus b. Address bus c. Control bus d. Internal bus

23. IC is the instruction count, CPI is the average number of system clock periods to execute per instruction and is the duration of a clock period. Then which one of the following expresses the execution time? a. IC * CPI* b. IC*CPI/ c. IC* /CPI d. CPI* /IC

24. Four 8-input multiplexers drive a single 4-input MUX. What is the result? a. 4-input MUX b. 8-input MUX c. 12-input MUX d. 32-input MUX

25. There are N processes in the memory. A process spends a fraction 1 of its time in I/O wait state. Which one of the following expresses the CPU utilization? a. P b. 1– P c. PN d. 1–PN

26. Any computer uses three different memories called: 1. Cache memory 2. Virtual memory 3. Main memory Moving from the CPU outwards, which is the correct order in which they appear? a. 1,2,3 b. 1,3,2 c. 3,1,2 d. 2,3,1

27. What is the function of a program counter in an 8-bit microprocessor? a. To store the op-code of the instruction

being executed b. To store the op-code of the next

instruction c. To store the address of the instruction

being executed d. To store the address of the next

instruction 28. An 8085 P is executing the program

given below: MVI A, 10 H MVI B, 10 H BACK: NOP ADD B RLC JNC BACK HLT

How many times the instruction NOP will be executed? a. 1 b. 2 c. 3 d. 4

29. What is the effect of a DAD H instruction? a. To shift each bit one position to the

right with a zero inserted in MSB position

b. To shift each bit one position to the left with a zero inserted in LSB position

c. To shift each bit one position to the right

d. To shift each bit one position to the right

30.

4 of 14 In the circuit shown in the figure above,

the switch S is closed at t = 0. Which one of the following gives expression for the voltage across the inductance as a function of time?

a. / 2te

b. 1 / 2te

c. 1 te

d. te 31.

For the circuit shown above, the current flowing through 1 resistor is adjusted to zero by varying the value of R. What is the value of R? a. 2 b. 3 c. 4 d. 6

32.

What is the Thevenin’s equivalent between A and B for the circuit shown above? a. 12V, 3/2 b. 4V, 3/2 c. 16/3 V, 2/3 d. 16/3 V, 3

33.

For the circuit shown above, the initial capacitor voltage is 2 V and I si a unit step function. Then, what is the expression for V(t) for t> 0?

a. 2 te

b. 22 te

c. 21 te

d. 21 te 34. Which is the correct sequence of the

devices in the increasing order of turn-off times? a. MOSFET–IGBT–BJT–SCR b. IGBT–MOSFET–BJT–SCR c. SCR–BJT–MOSFET–IGBT d. MOSFET–BJT–IGBT–SCR

35.

In the circuit shown in the figure above,

steady state is reached with switch S open. Switch S is then closed at t = 0. what is the value of voltage V under steady state (When t= )? a. 50V b. 12.5V c. 25V d. 0V

36.

What is the coefficient of coupling for the

magnetically coupled circuit shown above , if L1, L2 and M are 1 H, 0.25 h and 0.4 H respectively? a. 0.2 b. 0.5 c. 0.8 d. 0.9

37.

What are the suitable values for Z1 and Z2

to make the input impedance, Zin, of the above network equal to R? a. R and R b. 2R and R

5 of 14c. 3R and 2 R d. 4R and 4 R

38. If f1(t) and f2(t) have the widths (duration) T1 and T2 respectively, then what is the width (duration) of f1 (t)* f2(t) (where * denotes convolution)? a. The larger of T1 and T2 b. The smaller of T1 and T2 c. The smaller of T1 and T2 d. T1–T2

39. What is sinc(t)* sinc (t) equal to? a. (t) b. U(t) c. Rect (t) d. Sinc(t)

40. What is the impulse response h(t) for a system specified by differential equitation

5 6 ( ) ( )?y y y t x t

a. 2 32t th t e e u t

b. 2 32t th t e e u t

c. 3 22t th t e e u t

d. 2 32t th t e e u t

41. Given 1, 0

0

t Tx t

otherwise

and

, 0 2

0

t t Th t

otherwise

Which one of the following represents the convolution of the above i.e.,

( * ?y t x t h t

42. Consider the following statements about a

silicon controlled rectifier 1. It is a four-layer three-terminal device. 2. A very small forward current flows

when the bias is below a critical value Vp.

3. For bias voltage V>VP the device conducts large current.

4. The value of Vp, decreases with increasing value of current in the third terminal.

Which of the statements given above are correct? a. 1, 2, 3 and 4 b. 1, 2 and 3, only c. 3 and 4, only d. 1 and 2, only

43. Match List I with List II and select the correct answer using the code given below the lists: List I (Signal) A. U(n)

B. nu n

C. 1u n

D. 1nu n

List II (R.O.C. in Z-domain) 1. | | | |Z

2. | | | |Z

3. | | 1Z

4. | | 1Z

A B C D a. 3 2 4 1 b. 3 1 4 2 c. 4 2 3 1 d. 4 1 3 2

44. What is the bandwidth in radian/s of the

system whose transfer function is 1

1s ?

a. 2 b. 1 c. 3 d. 4

45. Consider the block diagram:

Which of the block diagrams given above

can be reduced to transfer function

1

1 21

C s G

R s G G

?

a. 1 and 3

6 of 14b. 2 and 4 c. 1 and 2 d. 2 and 3

46. The closed-loop transfer function of a unity feedback control system is

2

25

10 25s s .What is the loop transfer

function of the system?

a. 2

25

10s s

b. 2

25

25s

c. 25

25s

d. 25

10s

47. Assertion (A): Magnetizing current of a 1-phase transformer with sinusoidal supply voltage is non-sinusoidal. Reason (R): Magnetization characteristics of transformer core is nonlinear. a. Both A and R are individually true and

R is the correct explanation of A. b. Both A and R are individually true but

R is not the correct explanation of A. c. A is true but R is false d. A is false but R is true

48. Assertion (A): Microcontrollers have the same architecture as a microprocessor. Reason (R): Microcontrollers find wide application in embedded system design. a. Both A and R are individually true and



49. Assertion (A): In the von Neumann architecture, the program execution is essentially sequential in nature. Reason (R): Programs are stored in the same memory as data, which has a single interface with the CPU. a. Both A and R are individually true and



50. Assertion (A): The reflected (or echo) signal coming to a radar receiver is very weak compared to the transmitted signal. Reason (R): Radar transmitter sends out large amplitude narrow pulses. a. Both A and R are individually true and



51. Assertion (A): Coherent FSK system is preferred over non-coherent FSK system. Reason (R): Coherent FSK, system requires less power than non-coherent FSK system. a. Both A and R are individually true and



52. Assertion (A): An op-amp can perform mathematical operations like scaling, addition, integration, differentiation etc. Such building blocks can be suitably connected to obtain an analog simulator. Reason (R): A differentiator is not used in an analog computer because it amplifies noise and other unwanted signals as its inputs. a. Both A and R are individually true and



53. Assertion (A): The rise time of response in a PI controlled system can be adjusted by varying the integral time constant. Reason (R): The rise time reduces when the integral time constant is decreased. a. Both A and R are individually true and



54. Assertion (A): If two signals are orthogonal they will also be orthogonal. Reason (R): If two signals are or tonsorial they also will be orthogonal.




55. Assertion (A): Inductors carrying steady direct currents act as effective short circuits with zero voltage across it. Reason (R): The voltage induced across an inductance is proportional to the rate of change of current di/dt. a. Both A and R are individually true and



56. Assertion (A): The transition or space charge capacitance of a reverse biased diode decreases with increase in reverse bias voltage. Reason (R): The space charge width decreases due to increase in reverse bias. a. Both A and R are individually true and



57.

The above figure represents the band

diagram of a metal oxide-semiconductor system.

The symbols have the usual significance. Which is the correct description of the semiconductor surface? a. There is accumulation of holes at the

oxide semiconductor interface b. The semiconductor surface is

completely depleted of charge carriers c. The band bending corresponds to the

onset of strong inversion d. The semiconductor surface lies in the

range between flat-band and sub threshold conditions

58. Which one of the following is the correct statement? The Hall coefficient of an n-type semiconductor is a. Negative and varies with temperature b. Negative and constant c. Positive and constant d. Positive and varies with temperature

59.

Fermi Dirac distribution function is plotted

for four different temperatures (T) as curves labelled 1 to 4. Match List-I with List-Il and select the correct answer using the code given below the lists:

List I A. 0 K B. 50 K C. 300 K D. 400 K List II 1. Curve-1 2. Curve-2 3. Curve-3 4. Curve-4

A B C D a. 1 2 3 4 b. 1 3 4 2 c. 4 3 2 1 d. 4 1 2 3

60. Match List I with List II and select the correct answer using the code given below the lists: List I A. Thermal voltage B. Current flow due to concentration

gradient of charge carriers C. Rate of change of carrier concentration D. Electric field intensity in terms of

charge density List II 1. Continuity equation 2. Poisson’s equation 3. Einstein equation 4. Diffusion equation

8 of 14A B C D

a. 3 4 1 2 b. 1 4 2 3 c. 3 1 4 2 d. 1 2 3 4

61.

In the above band diagram of a semiconductor, the Fermi level is 03 eV above the intrinsic level. What does the energy level E in the diagram represent? a. The Fermi level b. The intrinsic level c. The donor level d. The acceptor level

62. Which one of the following is the correct statement? In a p-type semiconductor a. The donor band is near to conduction

band b. The donor band is near to valence band c. The acceptor band is near the

conduction band d. The acceptor band is near to valence

band 63. Consider the following statements

regarding characteristics of super conductors 1. Resistively of super conductors is zero. 2. Magnetic flux density in super

conductors is zero. 3. The relative permeability of super

conductors is zero. 4. Transition from super conducting to

normal state under influence of magnetic field is irreversible.

Which of the statements given above are correct? a. 1, 2 and 3 b. 2, 3 and 4 c. 1, 3 and 4 d. 1, 2 and 4

64. In a fibre optic system, what are the source and detector, respectively? a. p-n junction laser and a photo diode b. p-n junction laser and an LED

c. LED and a BJT d. LED and a MOSFET

65. Which one of the following is the most suitable electric drive for large power, low speed, reversible drives? a. Cyclo converter fed 3 phase ac motor

drive b. CSI fed self-controller load

commutated synchronous motor drive c. Square wave voltage source inverter

fed 3 phase ac drives d. 3-phase induction motor drive fed from

a 3-phase ac voltage controller 66. A 3-phase induction motor is fed from a

variable frequency variable voltage source such that the air gap flux remains constant. Which one of the following is the correct statement? The armature current of the motor is a. Independent of rotor frequency but

dependent on stator frequency b. Independent of stator frequency but

dependent on rotor frequency c. Dependent on both stator and rotor

frequency d. Independent of both stator and rotor

frequency 67. For a distribution sub-station power

transformer, operating at normal voltage frequency, and with usual 24-hour urban domestic load-cycle, let the commercial efficiency be c and the all-day efficiency

be a .

Under the operating conditions stated above, which one of the following is correct? a. c a

b. c a

c. c a

d. c and a can not be compared, as they

have different units 68. A transformer has a reactance of 0.1 p.u.

and negligible resistance. What is its voltage regulation at full load, and 0•8 power factor lagging? a. 8% b. 6% c. –6% d. –8%

69. Which one of the following is the correct statement?

9 of 14Field control of d.c. shunt motor gives a. Constant kW drive b. Constant torque drive c. Constant speed drive d. Variable load speed drive

70. Match List-I with List-Il and select the correct answer using the code given below the lists: List I (Characteristics)

List II (Type of generators) 1. Shunt 2. Under compound 3. Over compound 4. Differential compound

A B C D a. 2 1 4 3 b. 4 3 2 1 c. 2 3 4 1 d. 4 1 2 3

71. What value of resistance represents the mechanical load in the equivalent circuit of a 3-phase induction motor? a. 2 /r s

b. 2 1 1/r s

c. 2 1/ 1r s

d. 2 1r s

72. A d.c. source supplies 100 A current to a 0.1 resistor. If the open circuit voltage of the source is 12 V, then what is its internal resistance? a. 0.1 b. 0.02 c. 2.0 d. 10.0

73. Open-circuit (O.C.) and short-circuit (S.C.) tests on a synchronous machine were performed at a certain excitation and rated speed. If the speed is increased by 10% keeping the excitation same, what is the increase/decrease in the O.C. voltage and the S.C. current, respectively? a. Increase by 10%, Increase by 10% b. Increase by 10%, remains same

c. Decrease by 10%, Decrease by 10% d. No increase, No increase

74. An under-excited synchronous motor is operating at no load on an infinite bus of voltage 1-0 p.u. and drawing a current of 08 p.u. Its synchronous reactance is 0.5 p.u. What is the p.u. value of its excitation emf? a. 1-4 b. 1.0 c. 0.6 d. 0.4

75. Match List-I with List-Il and select the correct answer using the code given below the lists: List I (Motor) A. Hysteresis motor B. Shaded-pole motor C. Reluctance motor D. Universal motor List II (Application) 1. Photocopying machine 2. Phonograph turntable 3. Electric Shaver 4. Record player

A B C D a. 4 3 2 1 b. 2 1 4 3 c. 4 1 2 3 d. 2 3 4 1

76. How is the magnetic field dH from a short section dl of a current carrying wire, given by Biot-Savart’s law expressed?

a. 2/ 4dH IDL r b. sin / 4dH IDL r

c. 2sin / 4dH IDL r

d. 2 2sin / 4dH Ir dL r 77. A potential field is given by:

23V x y yz .

Which one of the following expresses an electric field at P(2,-1,4)?

a. 12 8i j

b. 12i j

c. 12 8i j k

d. 12 8i j k

78. Which one of the following is not correct?

10 of 14a. Equation 0 vV may be

regarded as poisson’s equation for an inhomogeneous medium.

b. Two potential functions V1 and V2 satisfy Lap lace’s equation within a closed region and assume same values on its surface. Then, V1 and V2 must be equal to V2.

c. The capacitance of a capacitor filled with a linear dielectric is independent of the charge on the plates and the potential difference between the plates

d. A parallel plate capacitor connected to a battery stores twice as much charge with a given dielectric as it does with air as dielectric, then susceptibility of dielectric is 2.

79. Which of the following represents the Maxwell’s curl equation for static magnetic field?

a. 0b j

b. b o

c. ob

d. . 0b

80. Which one of the following statements is

correct? The FDM telephone system accommodate more channels by a. Increasing the multiplexer size b. Using many final carriers c. Narrowing the band width of each d. Using multiple level of multiplexing

81. If b(t)= data (stream of binary digits), Ps = power of the sinusoidal single A 0cos t

then what is the BPSK output?

a. 0.cossb t P t

b. 0. cossb t P t

c. 02 . cossb t P t

d. 02. cosb t t

82. In a PCM system with uniform quantization, increasing the number of bits from 8 to 10 will increase the signal to quantization noise ratio by which factor? a. 1.25 b. 8 c. 10 d. 16

83. Which one of the following is the correct statement? In a DM system, the chances of slope overload increase when the a. Modulating signal changes rapidly b. Modulating signal remains constant c. Pulse amplitude is increased d. Pulse rate is increased

84. Which one of the following is not a property of autocorrelation function

( )R ?

a. 0R R

b. R R

c. 0R s average power of the

waveform d. Power spectral density is Fourier

transform of auto correlation function for a periodic wave form.

85. Which one of the following cannot be the Fourier series expansion of a periodic signal?

a. 2cos 3cos3x t t t

b. 2cos 7cosx t t t

c. cos 0.5x t t

d. 2cos1.5 sin 3.5x t t

86. Which one of the following is the correct statement? A basic Bi CMOS inverter IC has a minimum of a. Four MOS transistors b. Two bipolar and two n-MOS

transistors c. Two bipolar, one p-MOS and one n-

MOS transistors d. Four transistors one each of npn, pnp,

n-MOS and oMOS 87. What is Flash AX?

a. A serial AX b. A parallel AX c. Partly a serial and partly a parallel AX d. Successive approximation ADC

88. Which one of the following is the correct statement? The clock signals are used in sequential logic circuits a. To tell the time of the day b. To tell how much time has elapsed

since the system was turned on

11 of 14c. To carry serial data signals d. To synchronize events in various parts

of the system 89. Which one of the following is executed by

a simple addition of an inverter to an S-R flip flop? a. D-flip flop b. J-K flip flop c. Master-slave flip flop d. T-flip flop

90. How many 4-input MUX are needed to implement a 256-input MUX? How many levels will there be? a. 85, 4 b. 85, 5 c. 80, 4 d. 21, 3

91.

Consider the logic circuit shown in the figure given above. The functions f1. f2 and f (in canonical sum of products form in decimal notation) are

1

2

3

, , , 8,9,10

, , , 7,8,12,13,14,15

, , , 8,9

f w x y z

f w x y z

f w x y z

Which one of the following is the function

3f ?

a. 9,10

b. 9

c. 1,8,9

d. 8,10,15

92.

For the logic circuit shown in the figure

above, what is the output y equal to?

a. ABC

b. AB BC

c. AB BC A B d. All of the above

93. In the fabrication of a p-n junction on n-type substrate, the processes involved are 1. Diffusion 2. Oxidation 3. Lithography 4. Metallization What is the correct sequence in which these processes are carried out? a. 2–3–4–1 b. 4–2–1–3 c. 2–4–3–1 d. 2–3–1–4

94. Three input NAND gate is to be used as an inverter. Which one of the following measures will achieve this end better? a. All inputs are connected together,

making one input b. The two inputs not used are connected

to the logic ‘1’ level c. The two inputs not used are connected

to ground ‘O’ level) d. None of the above

95. 10 mV input to an amplifier gives 5 V output without feedback. With negative feedback, 160 my input is required to give the same output. What is the feedback factor (13) used? a. 3% b. 5% c. 10% d. 16%

96. The output response of a dc amplifier to a step input shows 35 ns rise time. What is its bandwidth nearly equal to? a. 1 MHz b. 35 MHz c. 10 MHz d. 35 MHz

97. Consider the following statements 1. Common-drain amplifier is called

source follower. 2. For very large R5 (the resistance

connected between source and ground) the output impedance of a source follower is equal to i/gm.

3. The input impedance of a common gate amplifier is low.

Which of the statements given above is/are correct? a. 1 only b. 1 and 2, only c. 2 and 3, only

12 of 14d. 1, 2 and 3

98. Consider the following statements in connection with transistor amplifiers in class B and class AB mode 1. In the class B for low signal voltages at

the base, the collector current is zero. 2. In the class B, there is cross-over

distortion. 3. In the class AB with no signal the dc

power drawn is zero. Which of the statements given above are correct? a. 1, 2 and 3 b. 1 and 2, only c. 2 and 3, only d. 1 and 3, only

99. Consider the following statements regarding transistors Compared to a junction transistor, a FET 1. Has a large gain bandwidth product. 2. Is less noisy. 3. Has less input resistance? Which of the statements given above is/are correct? a. 1 only b. 1 and 3, only c. 2 only d. 1, 2 and 3

100. A Zener regulator has an input voltage from 15 V to 20 V and a load current from 10 mA to 20 mA. If the Zener voltage is 5 V, what is the value of the series resistance? (Assume Izmin = 0). a. 250 b. 500 c. 750 d. 1500

101. Match List-I (Diagram of Circuit) with List-Il (Name of the Circuit) and select the correct answer using the code given below the lists: List I

List II

1. Full-wave voltage doublers 2. Base clipping circuit or bottom clipper 3. Slicer circuit or two-level clipper 4. Clamping Circuit

A b c d a. 4 3 1 2 b. 1 2 3 4 c. 1 2 4 3 d. 4 1 2 3

102. What is the value of the departure angle of root locus from the complex pole at s = 2+j for

1 2 2

kG s H s

s s j s j

?

a. – 60° b. – 45° c. – 30° d. – 90°

103. Consider the open-loop transfer function of a system given by

2; 0

2 2 5

kk

s s s s

Which one of the following is correct? The root locus of the system has real axis

in the range. a. 3 0s b. 1 0s c. 2 0s d. 6 0s

104. The impulse response of a second order under-damped system starting from rest is given by 612.5 sin 8 , 0tC t e t t .

What are the natural frequency and the damping ratio of the system? a. 10 and 0-6 b. (b) 10 and 0-8 c. 8 and 0-6 d. 8 and 0.8

105.

13 of 14

What are the values of undraped natural

frequency and damping ratio respectively for the system shown in the figure above? a. 5 and 0.5 b. 25 and 0.5 c. 5 and 1 d. 10 and 0.5

106. Match the relationship of items given in List-I (Medium) with the List-Il (Expression for Intrinsic Impedance) and select the correct answer using the code given below: All symbols have their usual meanings.

List I A. Free space B. Perfect dielectric C. Partially conducting medium D. Conducting Medium List II

1. . 45

2. j

j

3.

4. 0

0

A B C D a. 1 2 3 4 b. 1 3 4 2 c. 4 2 1 3 d. 4 3 2 1

107. Match List-I with List-Il and select the correct answer using the code given below the lists: List I (Parameters) A. Reflection coefficient at input B. VSWR C. Input impedance D. Phase shift magnitude List II (Range of values) 1. 0 to 2. 1 to

3. –1 to +1 4. 0 to 2

A B C D a. 1 2 3 4 b. 1 4 3 2 c. 3 1 4 2 d. 3 2 1 4

108. Which one of the following is the correct expression for the specific speed n in rpm of a hydro power station turbine at n rpm, working for a head of h meters and producing P kW?

a. 5/4/sn n P h

b. 5/40.858 /sn n P h

c. 5/41.165 /sn n P h

d. None of the above 109. Which one of the following is the correct

statement? The electric field in a cylindrical conductor of a transmission line for electric power a. Is a non-zero constant from centre to

conductor radius R b. Is zero at the centre but rises very high

at the conductor outer surface c. Undergoes a linear rise from zero at

centre to a finite value at the conductor radius

d. Undergoes a linear decline from a finite value at the centre to zero at the conductor radius

110. If the power transmission line is modeled so as to relate the sending end voltage Vs and current Is to the receiving end voltage Vr and current Ir by the relationship

' ;s r r s r rV AV BI I CV DI

Then which one of the following expresses the output impedance of the transmission line?

a. /s s s sDV BI CV AI

b. /s s s sCV AI DV AI

c. /s s s sDV CI DV BI

d. /s s s sDV BI AV DI

111. In the load-flow study of a power system, one node is selected as a “slack” or floating bus-bar which supplies the losses in the network.

14 of 14Which one of the following is the correct statement? The characteristic of the “slack-bus” is that this node a. Is known by the magnitude of its

voltage only b. Is known by the phase of its voltage

only c. Is known by both the magnitude and

the phase of its voltage d. Has power constraints

112. Which one of the following is the correct statement? The receiving end voltage of a three-phase 50 Hz single circuit long power transmission line may exceed the sending end voltage during a. Peak load conditions b. Intermediate load conditions c. Light load conditions d. None of the above

113. Consider the following statements stating reasons for keeping strict limits on system frequency variations 1. The under frequency operation of the

power transformer is not desirable. 2. The accuracy of electric clocks is not

only a function of frequency error but also a function of integral of frequency error.

Which of the statements given above is/are correct? a. 1 only b. 2 only c. Both 1 and 2 d. Neither 1 nor 2

114. An unloaded three-phase star-connected alternator is shorted by a three-phase fault at its terminals. The generator neutral is earthed through impedance. Which of the following groups correctly represents the relationships among positive, negative and zero sequence components of voltages and currents? a. 1 2 0 2 01/ 2 , 0; , 0a a a a aV V V I I

b. 1 2 0 2 02 , 0; 1/ 2 , 0a a a a a aV V V I I I

c. 1 2 0 0, 0; 0a a a a aV V V I I

d. 1 2 0 1 0' ; 0a a a a aV V V o I I

115. What are the typical values of percentage bias of differential values used for generator and transformer protection? a. 5% and 20%, respectively b. Both 5%

c. Both 20% d. 20% and 5%, respectively

116. Which one of the following is correct statements? In HVDC systems the converter station and inverter stations are under a. Constant current control individually b. Constant extinction angle control

individually c. Constant extinction angle control and

constant current control respectively d. Constant current control and constant

extinction angle control respectively 117. Hardness of a magnetic material is

measured in what terms? a. Saturation magnetization b. Magnetic induction c. Retentively d. Coercive field

118. In the case of an insulator-like diamond, what is the value of band-gap? a. Zero b. 0.72 eV c. 1.22 eV d. 6 eV

119. Three materials (semi-conductors) are to be arranged in order of increasing band-gap. Which one of the following is the correct sequence? a. Ge-GaP-Si-Ca As b. Si-Ge-Ca As-GaP c. Ge-Si-Ca As-GaP d. Ca As-Si-GaP-Ge

120. Match List-I with List-II and select the correct answer using the code given below the lists: List I (Material) A. CdS B. Ga As C. Si D. Ga As P List II (Applications) 1. VLSI 2. Gunri diode 3. Visible LED 4. Photo conductive cell 5. Thermistor

A B C D a. 2 1 3 5 b. 2 3 4 5 c. 4 2 1 3 d. 1 2 3 4

1 of 14

1. What is the Hall voltage in Hall Effect

experiment for an intrinsic semiconductor? a. Finite and positive b. Finite and negative c. Zero d. Finite and the sign (positive or

negative) depends upon the strength of the applied magnetic field.

2. On what factor does the ratio of electrical mobility to the diffusion coefficient

(D) in a doped (n or p) semiconductor at a given temperature (T) depend? a. The carrier concentration b. The life time of the carriers c. Is independence of the carrier

concentration and life time of the carriers

d. On the doping density and the type of doping (n or o)

3. Consider the following statements for a super conductor: 1. A super conductor is a perfect

diamagnetic 2. A super conductor has bound electron

pair within it. 3. A super conductor has bound electron

pairs within it. Current above a critical value passes though it.

Which of the statements given above are correct? a. 1,2 and 3 b. 1 and 3 only c. 2 and 3 only d. 1 and 2 only

4. Which one of the following materials has the highest value of dielectric strength? a. Rubber b. Nylon c. Mica d. Glass

5. The transition between two levels having energy difference of 1.6×10-19j produces light of wavelength 1240 nm. What would be the wavelength if the energy difference is 2.48eV? (1eV = 1.6×1019) a. 2.48 m

b. 1.24 m

c. 1.0 m

d. 0.5 m

6. Which one of the following statements is riot true for soft magnetic materials? a. Soft magnetic materials have high

eddy current losses b. Soft magnetic materials have low

hysteresis losses c. In soft magnetic materials domain wall

motion is easy d. Soft magnetic materials are used in

transformers 7. Consider the following important

characteristics of a frequency counter 1. Time base accuracy 2. Least significant bit count 3. Gain of the input amplifier The most important characteristics responsible for the overall accuracy of frequency measurement using the counter would include which of the characteristics given above? a. 1 and 2 b. 2 and 3 c. 1 and 3 d. 2 only

8. Which one of the following is the definition of the dead zone of an instrument? a. The time required by an instrument to

warm up initially b. The largest change of input quantity

for which there is no output of the instrument

c. The time required by the instrument to begin to respond to a change in the measurement

d. The unmeasured quantity which exceeds the maximum range of the instrument

9. Why guard circuit is used in the measurement of high resistance? a. To eliminate the capacitive effect b. To eliminate the error owing to

leakage current over insulation c. To guard the resistance against stray

electrostatic field

C.S.E Pre-2007


2 of 14d. To avoid damage caused by high

voltage used in measurement 10. Which one of the following is the main

advantage of bridge balanced TVM? a. It offers low input impedance b. Accuracy of calibration is maintained

over a wide range of temperature and fluctuations in power supply do not influence its performance

c. It offers high input impedance d. It is cheaper than VTVM

11. For measuring the signal level of individual harmonics in an unknown waveform, which of the following instruments are useful? 1. Distortion analyzer 2. Wave analyzer 3. Spectrum analyzer Select the correct answer using the, code given below: a. 1. and 2 only b. 2 and 3 only c. 1 and 3 only d. 1, 2 and 3

12. Two strain gauges are employed for the measurement of strain in a cantilever. One gauge is mounted on top of the cantilever and the other is placed at the bottom. The two .strain gauges form two arms of a voltage sensitive Wheatstone bridge, What is this bridge configuration? a. Full bridge b. Half bridge c. Quarter bridge d. Null bridge

13. Under which condition (s) are digital data acquisition systems used? a. Physical quantity being monitored has

a narrow bandwidth b. High accuracy is required c. Per channel cost is low d. All of the above

14. Among single - phase induction motors which one of the following motors has the least starting torque in per unit terms? a. Split- phase motor b. Capacitor motor c. Capacitor start motor d. Shaded-pole motor

15. An induction motor has a slip of 4% at full load. If its starting torque is equal to the

full load torque, Then what is the starting current? a. Equal to the full load current b. Four times the full toad current c. Five times the full load current d. Twenty five times the full load current

16.

A 2200 V/220V auto-transformer, shown in the figure above has its primary coil AS connected to the common line at point C. The secondary side is between D and C. Now, if there is a disconnection between the terminals B and C, while the transformer is energized at the primary side with. 2200 V, neglecting internal impedances of the transformer, what is the voltage V2 on the secondary side? a. 2200 V plus 220 V b. 2200 V minus 220 V c. 2200 V d. 220 V

17. A differentially compounded d.c. motor drives a constant horse power load, if the series field winding is short circuited then which one of the following will happen? a. Armature current will decrease and

speed will increase b. Armature current will increase and

speed will also increase c. Armature current will decrease and

speed will decrease d. Armature current will decrease and

speed will also decrease 18. Consider the following statements

Dual - slope integration type Analog -to- Digital converters provide 1. Higher speeds compared to all other

types of A/D converters 2. Very good accuracy without putting

extreme requirements on component stability

3. Good rejection of power supply hums.

3 of 14Which of the statements given above is/are correct? a. 2 and 3 b. 1 and 2 c. 1 and 3 d. 3 only

19. Consider a multiplexer with X and Y as data inputs and Z as control input. Z = 0 selects inputs X and Z = 1 selects inputs Y. What are the connections required to realize the 2- variable Boolean function f = T + R, without using any additional hardware? a. R to X, 1 to Y, T to Z b. T to X, R to Y, T to Z c. T to X, R to Y, 0 to Z d. R to X, 0 to Y, T to Z

20. What voltage is used to operate ECL gates? a. +5V b. -5V c. +15V d. Varies between 0 and 30V

21. When a time varying signal has to be digitized using an ADC, which one of the following is necessary to use before digitization? a. A time division multiplexer b. A frequency division multiplexer c. A sample and hold circuit d. An instrumentation amplifier

22. A 10 bit ND converter is used to digitize an analog signal in the 0 to 5 V range. What is the maximum peak to peak ripple voltage (approximate) that can be allowed in the D.C. supply voltage? a. 200 my b. 50 mV c. 25 mV d. 5 mV

23. How is a voltage control bus specified in load flow studies of a power system? a. By real power and reactive power b. By real power and voltage magnitude c. By voltage and voltage phase angle d. By reactive power and voltage

magnitude 24. The corona loss on a particular system at

50 Hz is 1 kW/km per phase . What would be the corona loss at 60 Hz? a. 0.83 kW/km per phase

b. 1 kW/km per phase c. 1.13 kW/km per phase d. 1.2 kW/km per phase

25.

The distribution system shown in the

above figure is to be protected by over-current system of protection. For proper fault discrimination, directional over - current relays will be required at which location? a. 1 and 4 only b. 2 and 3 only c. 1, 4 and 5 d. 2, 3 and 5

26. Consider the following statements The purpose of compensating a transmission line is 1. To improve the system stability. 2. To improve the efficiency 3. To reduce the Ferranti effect Which of the statements given above are correct? a. 1, 2 and 3 b. 1 and 3 only c. 1 .and 2 only d. 2 and 3 only

27. What is the structure of an ACSR conductor? a. Steel strands forming central core,

around which are aluminum strands b. Aluminum strands forming central

core, around which are steel strands c. Aluminum and steel strands are

alternately placed and formed into a conductor

d. Aluminum and copper alloy are stranded to form the conductor

28. What is the purpose of the moderator in a nuclear power plant? a. To control the, flow of water inlet b. To control the amount of nuclear fuel

into the reactor c. To control the nuclear fission or fission

rate by slowing down the neutrons

4 of 14d. To control the steam flow to the

turbine 29. If Iai is the positive sequence current of an

alternator and Z1, Z2 and Z0 are the sequence impedances of the alternator. What is the drop produced by the current Ia1? a. 1aiI Z

b. 1 1 2aI Z Z

c. 1 1 2 0aI Z Z Z

d. None of the above 30. Which property of SF6 gas makes it most

suitable for use in circuit breakers? a. Higher dielectric strength b. Higher molecular weight c. Higher dielectric strength and higher

molecular weight d. Lower molecular weight

31. A 3-phase full-bridge diode rectifier is fed from delta-star transformer. The voltage fed to the rectifier has a maximum value of V2 from line to neutral so that the voltage of phase ‘a’ IS Va = Vm sin t. The phase sequence is a-b-c. At the instant the phase ‘a’ voltage is passing through zero, what will be the rectifier output voltage? a. Zero b. Vm

c. 2 mV

d. 3 mV

32. When compared with a common emitter connection what does the common base connection of B)T have? a. Lower output impedance b. Higher input impedance c. Higher current gain d. Lower current gain

33. In an armature voltage controlled separately excited d.c. motor drive with closed loop speed control, why is an inner current loop useful? a. It limits the speed of the motor to a

safe value b. It helps in improving the drive energy

efficiency c. It limits the peak current of the motor

to the permissible value d. It reduces the steady state speed error

34. In a chopper circuit, given that Edc = 50 V, R = 80 Ohm and duty cycle = 30%. What

is the average value of the thyristor current? a. 009375 A b. 0.1875 A c. 0.3750 A d. 0.625 A

35. When does a fully controlled line commutated converter operate as an inverter? a. In the range of firing angles

0 90 b. In the range of firing angles

90 180 c. In the range of firing angles

90 180 when there is a suitable d.c. source in the load

d. When it supplies a back e.m.f. load 36.

What is the encoding format for digital data shown in the above figure? a. NRZ-L b. NRZ-I c. Manchester d. Bipolar-AMI

37. A spherical volume of radius ‘a’ has a uniform charge density . What is the electric displacement 0 on the surface of the sphere?

a. 34 / 3 a

b. 2a

c. 1/ 3 a

d. 24 / 3 a

38. An electromagnetic field in free space 0 0, is given by:

0

00 0

0

cos 0 /

cos /

x

y

E a E t k zV M

H a E t k z A m

Where 0 0 0k . What is the average

power per unit area associated with this wave?

a. 20 /za E

5 of 14

b. 20 /120za E

c. 20 / 240za E

d. 20 / 300za E

0

0

120Given

39. An infinitely long line charge of density . lies along z - axis. What is the electric field at a point (R, 0, 0)?

a. ˆ / 4za R

b. 0ˆ / 2ya R

c. 0ˆ / 2xa R

d. ˆ / 2xa R

40. Match List-I with List-Il and select the correct answer using the code given below the lists: List I

A. . 0P

jt

B. 0D

H jt

C. B

Et

D. .D P

List II 1. Modified Kirchhoff’s Current Law 2. Modified Ampere’s Law 3. Faraday’s Law 4. Gauss’ Law

A B C D a. 1 2 3 4 b. 4 3 2 1 c. 1 3 2 4 d. 4 2 1 3

41. A wave propagating in a lossless dielectric has the field components:

7500cos 10 /xE t z a V m

and

7500cos 10 /

180 yH t z a A m

If the wave velocity is 1.5×108 m/s, the medium has a. 4, 1r r

b. 3, 4 / 3r r

c. 1, 4r r

d. 2.25, 1r r

0

0

120Given

42. What is the variation of near - zone electric field of a Hertz Ian dipole with radial distance R from the dipole? a. 1/R b. 1/R2 c. 1/R3 d. 1/R5

43. For a parallel plate transmission line with perfectly conducting plates of. width and separated by a lossless dielectric slab of thickness d, the characteristic impedance zo is p times the intrinsic impedance of the dielectric medium where a. /p d

b. /p d

c. /p d

d. /p d

44. For similar field distribution (not identical) the highest Q factor can be obtained from which one of the following cavities? a. Rectangular cavity b. Circular cavity c. Spherical cavity d. Co-axial cavity

45. Which one of the following is correct? A particular mode in a cavity resonator can be excited by introducing a probe inside the cavity at a location where a. The electric field is a maximum b. The electric field is a minimum c. The magnetic field is a maximum d. The magnetic field is a minimum

46. Which one of the following is correct? Flat-top sampling of low pass signals a. Gives rise to aperture effect b. Gives rise to impulse over sampling c. Leads to abasing d. Introduces delay distortion

47. Match List-I with List-II and select the correct answer using the code given below the lists: List I (Dicrete-time LTI system Description with input x[n] and output u[n] A. y[n] = x[n] + x[n—1] B. y[n)= x[n] C. y[n] = y[n –1] + x[n]

6 of 14D. y[n] = x[n] –y[n –1] List II (System Transfer function)

1. 11/ 1 z

2. 11/ 1 z

3. 11 z

4. 1 A B C D

a. 4 3 2 1 b. 3 4 1 2 c. 4 3 1 2 d. 3 4 2 1

48. If 2

2 1

2 5

sF s

s s

, then what are values

of 0f and f respectively?

a. 0,2 b. 2,0 c. 0,1 d. 2/5,0

49. The lengths of two discrete time sequences x1 (n) and x2 (n) are 5 and 7, respectively. What is the maximum length of the sequence x1 (.n) * x2 (n)? a. 5 b. 6 c. 7 d. 11

50. Which one of the following statements is correct? Spectral density of a real valued random process has a. An even symmetry b. An odd symmetry c. A conjugate symmetry d. No symmetry

51. Which of the following are correct for a semiconductor SRAM? 1. It is volatile 2. It needs refreshing 3. It is built using flip-flops. Select the correct answer using the code given below: a. 1,2 and 3 b. 1 and 2 only c. 2 and 3 only d. 1 and 3 only

52. Match List-I with List - II and select the correct answer using the code given below the lists:

List I A. SID,SOD B. READY C. TRAP D. ALE List II 1. Wait state 2. Interrupt 3. Serial data transfer 4. Memory of I/O read/write 5. Address latch control

A B C D a. 3 1 5 2 b. 3 1 2 5 c. 4 3 2 5 d. 4 3 1 2

53. A memory system of size 16 K bytes is required to be designed using memory chips which have 12 address lines awl 4 data lines each. What is the number of such chips required to design the memory system? a. 2 b. 4 c. 8 d. 16

54. Consider an N - bit carry look ahead adder. As N increases, the number of gates required grows in proportion to which one of the following? a. N b. N2 c. N d. N4

55. Consider the following statements Microcontrollers support “embedded” applications because 1. The control software is so small that it

can be embedded within the microcontroller’s ROM.

2. Since minimum external circuitry is required, the microcontroller can be embedded within a product.

3. A hard disc can be embedded within the computer system supporting the application.

Which of the statements given above is/are correct? a. 1, 2 and 3 b. 2 and 3 only c. 1 and 2 only

7 of 14d. 3 only

56. How many locations of memory space are there between locations B 123 and C 122 inclusive? a. 4K b. 8K c. 12K d. 16K

57. Which one of the following statements is correct? The ALE line of Intel 8085 microprocessor is used to a. Latch the output of an I/O instruction

into an external latch b. Deactivate the chip - select signal from

memory devices c. Latch the 8 bits of address lines AD7-

ADO into an external latch d. Find the interrupt enable status of the

TRAP interrupt 58. In 8085 with 2 MHz clock frequency, what

is the time delay obtained after execution of 4 NOP instructions? a. 4 s

b. 10 s

c. 8 s

d. 6 s

59. Match List-I with List-Il and select the correct answer using the code given below the lists: List I (Functional Unit) A. ALU B. I/O C. Primary Memory List II (Technique /Function) 1. Interleaving 2. Boolean operations 3. DMA

A B C a. 1 3 2 b. 2 1 3 c. 1 2 3 d. 2 3 1

60. Let A = 1111 1010 and B = 0000 1010 be two 8-bit 2’s complement numbers. What is their product n 2’s complement? a. 1100 0100 b. 1001 1100 c. 1010 0101 d. 1101 0101

61. Assertion (A): Bulk Si ingots are purified by the vertical zone refining process without using a crucible Reason (R): The vertical process of zone refining avoids the contamination of the material by the impurities which could be in the crucible material, if used. a. Both A and R are individually true and



62. Assertion (A) : A 16-bit data contained in a certain location of a computer memory can be expressed in terms of four hexadecimal digits only Reason (R): The hexadecimal number system has a base that is four times the base of binary number system. a. Both A and R are individually true and



63. Assertion (A): Interstitial diffusion decreases the life - time of minority carriers in the Si-wafer as compared to substitution diffusion process. Reason (R): Interstitial diffusion does not affect the lattice structure to the extent as the substitution diffusion process affects a. Both A and R are individually true and



64. Assertion (A): A universal motor is essentially a d. c. series motor which can also be operated from a. c. source of same voltage, but needs certain modifications to counter the ill - effects of alternating fluxes in the yoke and poles, and the transformer e.m.f. induced in the armature coils. Reason (R): The yoke and the main field of a universal motor are laminated, and, compensating and interlope windings are required to be placed in the quadrate-axis of the stator.




65. Coherent demodulation of FSK signal can be effected using which one of the following? a. Band pass filters b. Discriminatory detection c. Correlation receiver d. Envelope detector

66. The Minimum Shift Keying (MSK) is special case of which one of the following? a. Amplitude Shift Keying b. Phase Shift Keying c. Frequency Shift Keying d. QAM

67. A super heterodyne receiver with an LF. of 450 kHz is tuned to a signal of 1200 kHz. What is the image frequency? a. 750 kHz b. 900 kHz c. 1650 kHz d. 2100 kHz

68. In a PCM system, the signal to quantization noise ratio is to be held to a minimum of 40 dB. The number of quantization levels to achieve this, should be close to which one of the following? a. 65 b. 85 c. 105 d. 130

69. If AM index changes from 0.5 to 0.7, what would be the change in ratio of the transmitted power to carrier power? a. 0.05 b. 0.08 c. 0.12 d. 0.15

70. What is the autocorrelation function of a rectangular pulse of duration T? a. A rectangular pulse of duration 2T b. A rectangular pulse of duration T c. A triangular pulse of duration 2T d. A triangular puise of duration T

71. Out of the four signal waveforms - sinusoid, rectangular, triangular and saw-

tooth, all of them having the same periodicity, the minimum bandwidth corresponds to which one of the following? a. Sinusoidal b. Rectangular c. Triangular d. Saw-tooth

72. Which one of the following statements is correct? Compared to a FDM system, a TDM system a. Needs lower bandwidth b. Gives lower signal to noise ratio c. Gives higher signal to noise ratio d. Uses simpler circuits

73. Which one of the following statements is correct? Power spectral dentistry, appropriately normalized, has the properties usually associated with a/an a. Ergodic process b. Autocorrelation c. Profanity density function d. Cumulative distribution function

74. What is the period of the function

cos 1 / 4f t t ?

a. 8s b. 4s c. 1/4s d. 1/8s

75.

Which one of the following conditions must be satisfied by the optimal value of the time constant RC, if in the envelope detector circuit shown above, the output e0 of the detector follows the envelope of the modulating signal without clippings?

a. 21

m

mRC

m

b. 21

1/ m

mRC

m

9 of 14

c. 2

1/1

m

mRC

m

d. 21

1/ m

mRC

m

(Symbols have usual meaning) 76. An FM signal with sinusoidal modulation

is considered. The modulation frequency is 6 kHz and the maximum deviation is 10 kHz. What is the band width (using Carson’s rule)? a. 8 kHz b. 16 kHz c. 32kHz d. 64 kHz

77. What is the purpose of television interlacing? a. To produce motion of the picture b. To scan all the lines on the screen c. To avoid flicker d. To simplify synchronizing pulses

78. What is the purpose of Instrument Landing System (ILS)? a. To pick up the radio transmission from

one or more control centers to determine the course of the vehicle

b. To determine the delay in arrival of back scattered echo to calculate the range of the vehicle

c. To guide vehicle in the runway by beaming special radio single from the airport

d. To measure the distance from the control centre using special equipment using radio signals

79. Consider the following statements about conductivity of a metal 1. Conductivity of divalent metals is

more than that for monovalent metals because the number of free electrons in the former is more

2. Conductivity of metals decreases with increasing temperature.

3. Mean free path of free electrons decreases with the addition of impurity atoms leading to a decrease in conductivity. V

Which of the statements given above are correct? a. 1, 2 and 3 b. 1 and 2 only c. 2 and 3 only

d. 1 and 3 only 80. What does a single bit magnitude

comparator have? a. Two inputs and one output b. One input and two outputs c. Two inputs and three outputs d. Three inputs and two outputs

81.

On a 1 out of 4 selector, the signals w

through z have been connected as described above. The circuit realizes the logic function S in the variables w through z. In a Karnaugh map of four variables, the function S gives what number of ones? a. Six b. Seven c. Eight d. Nine

82. Given that m denote midterm and M denotes maxterm, if 0 2 7, , ,f x y z m m m

Which of the following statements are correct?

1. 0 2 7' , , ,f x y z M M M

2. 0 2 7' , , ,f x y z M M M

3. 1 3 4 5 6' , , , , ,f x y z M M M M M

4. 1 3 4 6' , , , , ,f x y z m m m m

Select the correct answer using the code given below: a. 2 and 3 b. 3 and 3 c. 1 and 2 d. 1 and 4

83.

10 of 14 A zener diode regulator given in the above

figure is designed to meet the specifications:

IL = 10mA, V0=10V and Vin varies from 30V to 50V. The zener diode has Vz=10V and Izk (knee current) = 1mA.

Which one of the following conditions is approximately required for satisfactory operation? a. R ≤ 1800 Ohms b. 2000 Ohms ≤ R ≤ 2200 Ohms c. 3700 Ohms ≤ R ≤ 4000 Ohms d. R > 4000 Ohms

84. Match List I with List II and select the correct answer using the code given below the lists: List I (Biasing Circuit) A. Base bias B. Emitter-feedback C. Collector-feedback bias D. Voltage divider bias List II (Characteristics) 1. Not used in linear circuits 2. Needs very large resistance 3. Universal bias 4. Self bias

A B C D a. 1 2 3 4 b. 2 1 3 4 c. 1 2 4 3 d. 2 1 4 3

85. Consider the following: External frequency compensation is used in an OP-AMP to increase which of the following? 1. Open-loop gain 2. Stability 3. Input impedance 4. CMRR Select the correct answer using the code given below: a. 1 and 2 b. 2 only c. 4 only d. 3 and 4

86.

For the OP-AMP circuit shown above, what is the value of the amplification /v out inA V V ?

(Assume ideal OP-AMP) a. + 1 b. + 10 c. + 11 d. – 10

87. Match List I with List II and select the correct answer using the code given below the lists: List I (COM positive devices) A. Parallel connection B. Cascode connection C. Darlington connection D. Cascade connection List II (Diagram)

A B C D

a. 4 3 2 1 b. 1 2 3 4 c. 4 2 3 1 d. 1 3 2 4

88. Match List I with List II and select the correct answer using the code given below the lists: List I (Amplifier) A. RC-coupled amplifier B. Differential amplifier C. Cascade amplifier D. Tuned amplifier List II (Type of signals Amplified) 1. Video 2. Audio 3. Dc 4. Dc and audio 5. Narrow band

A B C D a. 5 3 1 2

11 of 14b. 2 1 4 5 c. 5 1 4 2 d. 2 3 1 5

89. Consider the following statements Proper biasing 1. Stabilizes the operating point of the

transistor 2. Increases the dynamic range of the

transistor 3. Changes the transistor into a linear

device 4. Reduces the distortion Which of the statements given above are correct? a. 1, 2 and 3 b. 1, 2 and 4 c. 1, 3 and 4 d. 2, 3 and 4

90. A Silicon BJT has a leakage current 1cac of 10 nA at 300 C. If the temperature rises to 600 C, what is the leakage current? a. 20 nA b. 40 nA c. 80 nA d. It shall remain unchanged

91. Which one of the following statement is not correct? a. Horizontal microinstructions have long

formats b. Horizontal microinstructions have the

ability to express a high degree of parallelism

c. Horizontal microinstructions are broadly similar to RISC instructions

d. Horizontal microinstructions involve little encoding of the control information

92. A computer takes 100 ns to access main memory and 20 ns to access an associative cache memory. With a 90% hit ratio, what is the average access time? a. 28 ns b. 30 ns c. 92 ns d. 100 ns

93. Match List-I with List-IT and select the correct answer using the code given below the lists: List I (Function) A. Continues to block lower priority

interrupts until it receives an EOJ command

B. Enables synchronous and asynchronous serial communication

C. Has I/O ports which can be configured as input ports, output ports or can be used to produce control signals

D. Can be programmed to handle all I/O tasks as well as carry out some data processing

List II (Chip) 1. 8255 2. 8089 3. 8259 4. 8251

A B C D a. 4 3 1 2 b. 3 1 2 4 c. 4 1 2 3 d. 3 4 1 2

94.

A part of an electrical network has the configuration shown in the figure above. The voltage drops across the resistances are 20 V, 30 V and 65 V with respective polarities shown in the figure. Which one of the following gives the correct value of the resistance R3? a. 13 b. 5 c. 65 d. 65/17

95.

What is the current I in the circuit given

above? a. 0 b. 1A c. 2A d. 3A

96.

12 of 14

In the circuit given above when R is

infinite, V= 4 volts and when R = 0, the current through R is 4A. if R = 3what is the current through it? a. 4A b. 3A c. 2A d. 1A

97.

For the circuit given above, what is the

current delivered by the battery? a. 3.0 A b. 2.0 A c. 1.0 A d. 0.0 A

98.

The circuit shown above is in steady-state

with the switch open. At t = 0, the switch is closed. What is the current through the 1 resistor [i(0+)]? a. 0 b. 1.33 A c. 1.66 A d. 2A

99.

In the circuit shown above, the inductor current is initially zero. The switch is closed at t = 0. Which one of the following gives the correct expression for the current i(t) for t > 0? a. 10 e – 0.5t b. 10 (1– e –20t) c. 10 (1– e – 05.t) d. 10

100.

What is the power consumed by the 1

resistor in the circuit shown above in the figure? a. 30 W b. 50 WW c. 100 W d. 130 W

101.

For the system represented by the above

block diagram, what is the overall transfer

function

C s

R sequal to?

a. 2

10

10s s

b. 2

10

11 10s s

c. 2

10

9 10s s

d. 2

10

2 10s s

102. The transfer function of a phase-lead

compensator is given by 1 3

1

TsG s

Ts

where T > 0 What is the maximum phase-shift provided by such a compensator? a. 30° b. 45°

13 of 14c. 60° d. 90°

103. The system matrix of a continuous time

system is given by 0 1

3 5A

What is the characteristics equation?

a. 2 5 3 0s s

b. 2 3 5 0s s

c. 2 3 5 0s s

d. 2 2 0s s 104. Which one of the following is correct?

A system with gain margin close to zero dB or a phase margin close to zero degree is a. Highly stable b. Oscillatory c. Relatively stable d. Unstable

105. A system is described by the characteristic equation given by

3 24 10 5 0s s K s K

What is the range of K for stable operation? a. 0 20K b. 0 40K c. 0 60K d. 0 80K

106. Consider the function:

2

5

2F s

s s s

where F(s) is the Lap

lace transformer of f(t).

What is limx

f s

equal ti?

a. 5 b. 5/2 c. Zero d. Infinite

107. A lead compensator is descried by the

function s

s

what are the relative values

of and ?

a.

b.

c.

d.

108. Consider the unit step response of a unity feedback control system whose open loop

transfer function is given by

1

1s s

What are values of the natural frequency of oscillation and the damping ratio? a. 1, 1n

b. 1, 0.5n

c. 0.5, 1n

d. 0.5, 0.5n

109. What is the necessary and sufficient condition to guarantee the stability of a discrete-time LTI system?

a. | |k

h K

b. | | 1k

h K

c. 0

| |k

h K

d. 0

| | 1k

h K

110. On what factors does the ripple frequency of a 3-phase semi converter depend? a. Firing angle and load resistance b. Firing angle and load inductance c. Firing angle and supply frequency d. Load resistance and load inductance

111. When compared with BJTs, MOSFETs have lesser turn off time, enabling them to operate at high operating frequencies. What is the reason that can be attributed to that property? a. High input impedance of the

MOSFETs b. Positive temperature coefficient of the

MOSFETs c. The absence of minority storage charge

in the MOSFETs d. Smaller leakage current of MOSFETs

112. Which one of the following expresses the thermal resistance between the body of a power semiconductor device and the ambient? a. Voltage across the device divided by

current through the device b. Temperature difference between body

and ambient divided by average power dissipated in the device

14 of 14c. Average power dissipated in the device

divided by the square of the RMS current in the device

d. Average power dissipated in the device divided by the temperature difference between body and ambient

113. Consider the following statements Resistances in integrated circuits are 1. Avoided since they contribute to power

dissipation 2. Included to increase current drain 3. Values of 50k and above 4. Avoided due to difficulty in fabricating

the values required Which of the statements given above is/are correct? a. 2 and 3 b. 1 only c. 1 and 4 d. 2 only

114. Is it possible for a thin film of Silicon to be grown on Al2O3 substrate by epitomical process? a. It is possible since Silicon and Al2O3

have different crystal structures and help in growth

b. It is not possible since they will react to form SiO2

c. It is possible since Silicon and Al2O3 have same crystal structure

d. It is not possible 115. Copper has a much lower resistively than

that of aluminum. SiO2 has a dielectric constant of 3.9 and Xerogel has a dielectric constant of 2.1. In order to reduce the interconnect delay in VLSI circuits, what should be the combination of metal and dielectric layer? a. Copper with SiO2 b. Aluminum with SiO2 c. Aluminum with Xerogel d. Copper with Xerogel

116. Why is a MOSFET with poly silicon gate preferred to a MOSFET with aluminum gate? a. The device becomes more resistant to

radiation

b. The gate can be self-aligned to source and drain

c. The isolation between adjacent devices is better

d. The gate leakage current is smaller 117. In semiconductor wafer cleaning, why is

tricolor-ethylene used? a. To remove dust particles from the

surface b. To remove grease from the surface c. To remove impurities from within the

crystal d. To remove moisture from the surface

118. Consider the following statements In a single-phase transformer at no load, if Silicon-steel laminations are replaced by aluminum laminations; then 1. Core flux would increase 2. Exciting current would rise 3. Power-factor would deteriorate 4. Magnetizing reactance would rise Which of the statements given above are correct? a. 1 and 3 b. 2 and 3 c. 1 and 4 d. 3 and 4

119. The low voltage winding of a 11,000/440 V, 1-phase 50 Hz transformer is to be connected to 25 Hz. In order to keep the magnetizing current at the same level as that for normal 50 Hz, what should be the supply voltage? a. 440 V b. 220 V c. 880 V d. 110 V

120. A 25 kVA, 2300/230 V, 50Hz, signal-phase transformer supplies rated load at 230V. The ratio of its leakage reactance to

resistance is 3 . The terminal voltage on reducing the load to zero is observed to be the same as at rated load. What is the power factor of the rated load? a. Unity b. 0.866 lagging c. 0.866 leading d. Zero leading

Civil Service - Electrical Engineering Prelims 1998-2007

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Transcript of Civil Service - Electrical Engineering Prelims 1998-2007