Eca [r10] April 2012

Code No: R22043

II B.Tech II Semester, Regular Examinations, April – 2012

ELECTRONIC CIRCUIT ANALYSIS

(Com. to ECE, EIE)

Time: 3 hours Max. Marks: 75

Answer any FIVE Questions

All Questions carry Equal Marks

~~~~~~~~~~~~~~~~~~~~~~

1. a) Perform the small signal analysis of CS Amplifier and explain the characteristics with the

help of relevant graphs.

b) For the emitter follower with Rs = 1 K and RL = 5 KΩ, determine the various characteristics

parameters by assuming h-parameters as hfe = 75, hie = 1.1K, hoe = 25 µA/v. (7M+8M)

2. a) Enumerate the effects of negative feedback on the various characteristics of the amplifier.

b) The open loop voltage gain of the amplifier of an amplifier is 50. Its input impedance is

1kΩ. What will be the input impedance where a negative feedback of 10% is applied to the

amplifier? (8M+7M)

3. a) Draw the circuit of Hartley oscillator and explain its working. Derive the expressions for

frequency of oscillation and condition for starting of oscillation.

b) A crystal has the following parameters:

L=0.33 H, Cs=0.0655 pF, Cp=1.0pF and R=5.5KΩ .

Find the series resonant frequency and Q-factor of the crystal. (10M+5M)

4. a) Perform the analysis of two stage RC Coupled JFET-CS Amplifier circuit.

b) Draw and explain the circuit diagram of a RC Coupled amplifier. Derive the expression for

voltage gain of the amplifier. (7M+8M)

5. a) Derive the expressions for resistive parameters of Hybrid-π model in terms of low frequency

h-parameters.

b) Following measurements of a certain transistor are available at room temperature and with Ic

= 5 mA, VCE=10V, hfe = 100, hie = 600Ω. [Aie] = 10 at 10MHz. Cc = 3pF. Calculate fβ, fT, Ce, rb’e

and rbb’. (8M+7M)

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6. a) Show that class B push pull amplifiers exhibit half wave symmetry.

b) A power transistor is to be used as a class A transformer coupled amplifier and is to deliver a

maximum of 5W to a 4 ohm load. Operating point is adjusted for symmetrical clipping with

collector supply voltage of 20V. Assume ideal characteristics with Vmin = 0 V.

Calculate.

i) Transformer turns ratio.

ii) Peak collector current

iii) Operating point values of ICQ and VCEQ.

iv) Power dissipation rating of transistor.

v) Collector circuit efficiency. (7M+8M)

7. a) Draw the circuit diagram of a double-tuned amplifier and explain different stages of

simplification of its equivalent circuit.

b) A circuit is resonant at 455 kHz and has a 10 kHz bandwidth. The inductive reactance is

1255Ω. What is the parallel impedance of the circuit at resonance? (8M+7M)

8. a) Draw the circuit and explain how short circuit over load protection is provided in Voltage

Regulators circuits.

b) Design a zener-shunt regulator with the specifications using a zener diode with Vz = 10 V.

Input supply voltage varies from 15V to 25V and the load current varies between 0 and 15 mA.

Also determine the line and load regulation. (7M+8M)

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Code No: R22043



(Com. to ECE, EIE)




~~~~~~~~~~~~~~~~~~~~~~

1. a) With the help of necessary equations, discuss the variations of Av, AI, Ri, Ro, Ap with RS and

RL in common Emitter configuration.

b) For the emitter follower with Rs = 1 K and RL = 5 KΩ calculate Ai, Ri, Av, Avs and Ro.

Assume hfe = 75, hie = 1.1K, hoe = 25 µA/v (7M+8M)

2. a) What are the different types of negative feedback? Explain how the input and output

impedances of an amplifier are affected by the different types of negative feedback.

b) The open loop gain of an amplifier is 50Db. A negative feedback of feedback factor 0.004 is

applied to it. If the open loop gain is thereby reduced by 10% find the change in the overall

gain.

c) How does negative feedback reduce distortion in an amplifier? (7M+5M+3M)

3. a) Derive the expression for the frequency of oscillation and the minimum gain required for

sustained oscillations of the RC phase shift oscillator using BJT.

b) Draw the equivalent circuit of a quartz crystal. What makes the quartz produce stable

oscillations? (10M+5M)

4. a) Draw the circuit for Darlington pair amplifier and derive the expressions for AI, Av, Ri and

Ro.

b) Three identical non-interacting amplifier stages are cascaded with an overall gain of 0.3dB

down at 50 kHz compared to mid-band. Calculate the upper cutoff frequency of the individual

stages. (8M+7M)

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Code No: R22043

5. a) Explain about Hybrid-π capacitances. How do Hybrid-π parameters vary with temperature?

b) The following low-frequency parameters are available for a transistor at

ICQ = 5 mA

hie = 1K, hfe = 100 hoe = 4 x 10-5

A/V

hre = 10-4

Cob = 2 pF fT = 10 MHz

Compute the values of hybrid-π parameters at room temperature. (7M+8M)

6. a) Draw the circuit diagram of class-B push pull amplifier and explain the operation.

b) Explain Class D and Class S power amplifiers. Mention their salient features and

applications. (8M+7M)

7. a) Draw the circuit diagram of a double-tuned amplifier and explain its working and derive the

expression for I2 max.

b) A single-tuned class A transformer-coupled RF amplifier has the following parameters:

Transconductance, gm of the transistor = 5mA/V

Primary inductance = 100 µH

Secondary inductance = 50 µH

Coefficient of coupling = 0.01

Primary resistance = 10 Ω

Secondary resistance = 8 Ω

The primary is tuned with a 100 pF capacitor and the secondary is loaded by a 10KΩ

resistance. Find:

The resonant frequency

The effective Q of the tuned circuit

The 3 dB bandwidth

Assume ro of the transistor to be very large. (7M+8M)

8. a) Define the terms i) Load Regulation ii) Line Regulation iii) Ripple Rejection and

iv) Temperature Stability pertaining to Voltage Regulator ICs.

b) 7824 regulator IC can deliver a maximum current of 700 mA. Design a circuit using same IC

to deliver a current of 3.0 A. (8M+7M)

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Code No: R22043



(Com. to ECE, EIE)




~~~~~~~~~~~~~~~~~~~~~~

1. a) Perform the small signal analysis of CD Amplifier and explain the characteristics with the


b) Consider a single stage CE amplifier with Rs = 1KΩ, Re = 50 K, R2 = 2K, Rc = 1K, RL =

1.2K, hfe = 50, hoe = hre = 0. hie = 1.1K. Find Ai, Ro, Av and power gain using approximate

analysis. (7M+8M)

2. a) Explain the general characteristics of negative feedback amplifiers.

b) A single stage CE amplifier has a Voltage gain of 600 without feedback. When feedback is

employed, its gain reduces to 50. Calculate the percentage of the output which is fed back to

the input. (8M+7M)

3. a) Explain the working of Wien Bridge Oscillator using BJT. Also derive the expression for the

frequency of Oscillation.

b) The ac equivalent circuit of a Crystal has the Values: L=3 H, CS=0.005pF, R= 2KΩ and

Cm=10 pF. Determine the series and parallel resonant frequencies of the Crystal. (8M+7M)

4. a) Perform the analysis of Boot-Strapped emitter follower Circuit.

b) Design a two-stage CE-CE amplifier for the given data. hfe1=hfe2=180, RL=1KΩ

IE1=IE2=1mA, S=3, VCC=12V, f=100Hz. Assume identical transistors. (7M+8M)

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Code No: R22043

5. a) Draw the equivalent circuit of hybrid-π model and derive the expressions for Hybrid-π

impedances in terms of low frequency h-parameters.

b) The following low-frequency parameters are available for a transistor at

IC =10 mA, VCE=10V and at room temperature

hie = 500Ω hfe = 100 hoe = 10-5

A/V hre = 10-4

At the same Operating point, fT=50 MHz and Cob = 3 pF

Compute the values of all the hybrid-π parameters. (8M+7M)

6. a) Deduce the expression which gives the relationship between maximum collector dissipation

and maximum power output of class-B push pull amplifier.

b) Write short notes on Heat Sinks used in power amplifiers and also give the classification.

(8M+7M)

7. a) Derive the expression for the gain of a single-tuned capacitance coupled amplifier. Discuss

about its Selectivity.

b) A parallel resonant circuit comprises of an inductor (having inductance of 1mH and

resistance of 10Ω) and a parallel capacitor of 100 pF.

Calculate:

i) Resonant frequency, ignoring the resistance.

ii) Resonant frequency, considering the resistance.

iii) Q-factor.

iv) Impedance at resonant frequency. (7M+8M)

8. a) Draw the circuit for series type voltage regulator and explain its working.

b) A series regulator has stability factor of 6*10-3

and output resistance of 10-4

ohms. Calculate

the change in output voltage when

i) Unregulated input d.c voltage varies by 10V.

ii) Load current varies by 250mA. (7M+8M)

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Code No: R22043



(Com. to ECE, EIE)




~~~~~~~~~~~~~~~~~~~~~~

1. a) Perform the small signal analysis of CG Amplifier and explain the characteristics with the


b) Consider a single stage CE amplifier with Rs = 1KΩ, Re = 50 K, R2 = 2K, Rc = 1K, RL =

1.2K, hfe = 50, hoe = hre = 0. hie = 1.1K. Determine Ai, Ro, Av and power gain using exact

method of Analysis. (7M+8M)

2. a) Explain the concept of feedback and draw the topologies of various feedback amplifiers.

b) Calculate the voltage gain, input impedance and output impedance of a voltage series

feedback amplifier having an open-loop gain A=300, Ri=1.5KΩ, Ro=50KΩ and ß= -1/20.

(7M+8M)

3. a) Perform the Generalized analysis of LC oscillators with suitable block diagram and Obtain

the circuit diagrams of Hartley and Colpitt’s oscillators.

b) Design a RC phase-shift oscillator, which has the following specifications: hfe=200,

IE=1.5mA, S=8, VCC=12V and oscillation frequency expected is 500Hz. (8M+7M)

4. a) Draw the circuit diagram of Cascode-transistor amplifier Circuit and analyze its

performance.

b) Draw the circuit diagram for differential amplifier and perform the analysis with its

equivalent circuit. (8M+7M)

5. a) Explain the concept of CE short circuit current gain with the help of equivalent circuit.

b) Following measurements of a certain transistor are available at room temperature and with Ic

= 5 mA, hfe = 100, hie = 0.62 KΩ. Short circuit current gain = Ais = 10 at 10MHz. Cbc = 3pF.

Calculate fT and fβ. (7M+8M)

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Code No: R22043

6. a) Derive the expression for maximum value of conversion efficiency of Class A Power

amplifier.

b) Ideal class – B transformer-coupled audio amplifier is fed from 20 V DC. Transformer ratio

is 4=s

p

N

N. A 4 ohm speaker is connected to load. Calculate:

i) Maximum signal power delivered to load.

ii) Power dissipation rating to each transistor.

iii) Maximum excitation current at input if transfer characteristic is linear (hfe = 20)

(7M+8M)

7. a) Draw the circuit diagram of double-tuned amplifier and simplify the same with its equivalent

circuit.

b) Draw the circuit for single tuned capacitive coupled amplifier and explain its working.

Derive the expression for (A/Areso) . (7M+8M)

8. a) Define different performance parameters of a voltage regulator and explain their importance.

b) Design a voltage regulator using IC 723 to provide an output voltage of 5 volts at 1.5A. Fold

back current limiting is to be provided so that knee current is 1.6A, short circuit current is

300mA and input voltage is 13 volts. (7M+8M)

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R10 SET - 4

Code No: R22031


MECHANICS OF SOLIDS (Com. to ME, AME, MM)




~~~~~~~~~~~~~~~~~~~~~~

1. a) Draw a typical stress-strain curve for mild steel, indicate salient point and define them

b) Compute the stresses at various sections and the total elongation of the bar shown in

Figure1. L1 = 4.0 m, L2 = 3.0 m, L3 = 2.0 m, A1 = 100 mm2, A2 = 400 mm

2 and A3 = 200 mm

2.

Es = 2.05 X 105 N/mm

2.

2. Draw the bending moment and shear force diagram for the beam loaded as shown in Figure 2.

Mark the values at the salient points. Determine the point of contra flexure also.

3. Compare the moment carrying capacity of the section given in Figure 3 with equivalent section

of the same area but

i) Square section

ii) Rectangular section with depth twice the width and

iii) A circular section.

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Code No: R22031

4. The unsymmetric I-section shown in Figure 4 is the cross-section of a beam, which is subjected

to a shear force of 100 kN. Draw the shear stress variation diagram across the depth.

5. Determine the forces in the members FH, HG and GI in the truss shown in Figure 5. Each load

is 10 kN and all triangles are equilateral with sides 4 m.

R10 SET - 1

Code No: R22031

6. A girder rests on two supports 5 m apart, and carries a distributed load of 60 kN, 2 m from one

support. Find the ratio of maximum deflection to deflection under load.

7. Calculate the increase in volume of a spherical shell of 1 m diameter 1 cm thick, when it is

subjected to internal pressure of 2 N/mm2, E = 2.1 x 10

6 N/mm

2 and poisons ratio is 0.3.

8. The maximum stress permitted in a thick cylinder of internal diameter and external radii 20 cm

and 30 cm respectively is 15.5 N/mm2. If the external pressure is 4 N/mm

2, find the internal

pressure that can be applied.

Plot the curves showing the variation of hoop and radial stresses through the material. What

will be the change in thickness of the cylinder? E = 2.1 x 105 N/mm

2 and µ = 0.3.

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Code No: R22031






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1. a) The Poisson’s ratio of a material as 0.3 and its young’s modulus value is 2.1 x 105 N/mm

2.

What is the value of shear modulus?

b) A steel rod of 20 mm diameter passes centrally through a tight copper tube of external

diameter 40 mm. The tube is closed with the help of the rigid washers of negligible thickness

and nuts threaded on the rod. The nuts are tightened till the compressive load on the tube is 50

kN. Determine the stresses in the rod and the tube, when the temperature of the assembly falls

by 500C. Take Es = 200 GN/mm

2, Ec = 100 GN/mm

2, αs = 12 x 10

-6 per

0C, αc = 18 x 10

-6 per

0C.

2. Draw the shear force and bending moment diagram of the beam shown in Figure 1. Mark the

values at the salient points.

3. A symmetric I-section of size 200 mm × 500 mm, 15 mm thick is strengthened with 300mm

×20 mm rectangular plate on top flange as shown is Figure 2. If permissible stress in the

material is 150 N/mm2, determine how much concentrated load the beam of this section can

carry at centre of 6 m span. Given ends of beam are simply supported.

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Code No: R22031

4. A beam has cross-section as shown in Figure 3. If the shear force acting on this is 50 kN, draw

the shear stress distribution diagram across the depth.

5. Find the forces in all the members of the truss shown in Figure 4 suing method of joints.

6. A uniform circular bar of diameter, d, and length, l, extends an amount, e, under tensile pull, P,

Show that the maximum deflection of the bar when it is used as beam simply supported at its

ends and carrying a central load, W, is given by .3 2

2

Pd

wel=δ Find the ratio of δ/e if l = 75d and

the maximum bending stress due to W is equal to the tensile stress under the pull, P.

7. A thin cylinder, 5 cm internal diameter and 1 mm wall thickness is closed at its end. And

subjected to an internal pressure of 1 N/mm2. Compute the longitudinal and hoop stress in the

cylinder.

8. A compound cylinder is formed by shrinkage one cylinder to another. The internal and external

radii of the compound cylinder are 15 cm and 24 cm respectively. All the junction radius is 21

cm. If after shrinkage on the radial pressure at the common surface is 5 N/mm2. Calculate the

initial stress across the section of the inner and outer cylinder. If the compound cylinder is

subjected to an internal pressure of 80 N/mm2, calculate the flexural stress induced.

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Code No: R22031






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1. a) A bar of uniform thickness‘t’ tapers uniformly from a width b1 at one end to b2 at the other

end in a length L. Find the expression for its extension under an axial pull P.

b) Tension test was conducted on a specimen and the following readings were recorded.

Diameter = 25 mm, Gauge length of extensometer = 200 mm

Least count of extensometer = 0.001 mm, at a load of 30 kN, extensometer reading = 60

At a load of 50 kN, extensometer reading = 100, Yield load = 160 kN

Maximum load = 205 kN, Diameter neck = 17 mm

Final extension over 125 mm original length = 150 mm

Find Young’s Modulus, yield stress, ultimate stress, percentage elongation and percentage

reduction in area.

2. Draw BM and SF diagrams for the beam shown in Fig. 1, indicating the values at all salient

points.

3. The cross-section of a cast iron beam is as shown in Figure 2. The top flange is in compression

and bottom flange is in tension. Permissible stress in tension is 30 N/mm2 and its value in

compression is 90 N/mm2. What is the maximum uniformly distributed load the beam can carry

over a simply supported span of 5 m?

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Code No: R22031

4. Draw the shear stress variation diagram for the I-section shown in Figure 3, if it is subjected to

a shear force of 200 kN.

5. Determine the forces in all the members of the truss shown in Figure 4 using method of joints

and indicate the magnitude and nature of forces on the diagram of the truss. All inclined

members are at 60° to horizontal and length of each member is 3 m.

6. A beam of uniform cross-section and of length, l, carries a uniformly distributed load, w, per

unit length. It is simply supported at the left hand end and at a point 1/3 inside the right hand

end. Show the deflection of overhanging end is EI

wl

648

4

, where E and I are the modulus of

elasticity and movement of inertia of the beam.

7. Calculate the increase in volume of a spherical vessel, 1 m diameter and 1 cm thick, when it is

subjected to increase in pressure of 2 N/mm2, E = 2.1 x 10

5 N/mm

2 and µ = 0.3.

8. A compound tube is made by shrinkage one tube on to another, the final dimensions being

internal diameter 10 cm external diameter 20 cm and the diameter at the junction between the

tubes is 15 cm. If the radial pressure between the tubes to be 20 N/mm2 find the stress in the

cylinder i) with no internal pressure and ii) with internal pressure of 100 N/mm2.

R10 SET - 3

Code No: R22031






~~~~~~~~~~~~~~~~~~~~~~

1. a) A tapering rod has diameter d1 at one end and it tapers uniformly to a diameter d2 at the

other end in a length L. If the modulus of elasticity is E, find the change in length when

subjected to an axial force P.

b) Derive the relationship between

i) Modulus of elasticity and modulus of rigidity

ii) Modulus of elasticity and bulk modulus.

2. Draw the bending moment and shear force diagram for the beam loaded as shown in Figure. 1.

Mark the values at the salient points Determine the point of contra flexure also.

3. a) Derive the bending equation. What are the assumptions made while deriving the bending

equation?

b) Figure 2 shows the cross-section of a cantilever beam of 5 m span. Material used is steel for

which maximum permissible stress is 150 N/mm2. What is the maximum uniformly distributed

load carried by the beam?

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Code No: R22031

4. A beam has cross-section as shown in Figure 3. If the shear force acting on this is 25 kN, draw

the shear stress distribution diagram across the depth.

5. Determine the forces in all the members of the truss shown in Figure 4 using method of joints

and indicate the magnitude and nature of forces on the diagram of the truss. All inclined

members are at 60° to horizontal and length of each member is 2 m.

6. Find the maximum deflection for the beam loaded as shown in Figure 5

7. Calculate the increase in volume enclosed by a boiler shell, 2.5 m long and 1 m in diameter,

when it is subjected to an internal pressure of 1.5 N/mm2. The wall thickness is such that the

maximum tensile stress in the shell is 25 N/mm2 under pressure. Take µ = 0.3.

8. The maximum stress permitted in a thick cylinder of internal diameter and external radii 25 cm

and 35 cm respectively is 10.5 N/mm2. If the external pressure is 3 N/mm

2, find the internal

pressure that can be applied.

Plot the curves showing the variation of hoop and radial stresses through the material. What

will be the change in thickness of the cylinder? E = 2.1 x 105 N/mm

2 and µ = 0.3.

R10 SET - 4

Code No: R22121


DATA COMMUNICATION

(Information Technology)




~~~~~~~~~~~~~~~~~~~~~~

1. a) Define Open Systems Interconnection. Explain about the OSI seven-layer International

Protocol hierarchy.

b) Define Signal analysis. Give a brief description of periodic signals. (8M+7M)

2. a) Explain about wave propagation on metallic transmission lines and metallic transmission

line losses.

b) Explain about the construction of Optical fiber. Also list the advantages and disadvantages

of Optical fiber cables. (8M+7M)

3. a) Define Pulse code modulation. Explain briefly about Pulse code modulation with suitable

diagrams.

b) Define Multiplexing. Explain briefly about Time-Division Multiplexing. (8M+7M)

4. a) Explain about Skip distance and Free-space path loss.

b) Describe in detail about Satellite Communication Systems. (8M+7M)

5. a) Discuss in detail about Basic Telephone Call procedures.

b) Explain in detail about Message-Channel noise and noise weighting. (8M+7M)

6. a) Explain about in detail about Mobile Telephone services.

b) Explain briefly about first generation Analog Cellular Telephone Systems. (8M+7M)

7. a) Describe character synchronization and explain the differences between Asynchronous and

Synchronous Data Formats.

b) Explain in detail about Bar Codes. (8M+7M)

8. a) Explain Voice-Band Modem with block diagram and also discuss its classifications.

b) Distinguish between 56K Modems and Cable Modems. (8M+7M)

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Code No: R22121


DATA COMMUNICATION





~~~~~~~~~~~~~~~~~~~~~~

1. a) Explain about various network topologies. Also give a brief description of network

classification.

b) Discuss briefly about Analog Modulation Systems. (8M+7M)

2. a) Define Transmission line. Describe about balanced and unbalanced transmission lines.

b) Explain briefly about the losses in Optical Fiber cables. (8M+7M)

3. a) Describe in detail about Companding.

b) Explain in detail about Frame Synchronization. (8M+7M)

4. a) Explain in detail about Rays and Wave fronts.

b) Describe in detail about Wave Attenuation and Absorption. (8M+7M)

5. a) Give a detailed description of Paging Systems.

b) Describe various Transmission Parameters in detail. (8M+7M)

6. a) Explain in detail about Cellular Telephone, Frequency Reuse and Interference.

b) What is United States Digital Cellular System? Explain briefly about its control and digital

voice channels. (8M+7M)

7. a) Describe in detail about Error-Detection mechanisms.

b) Determine the LRC and VRC for the following message (use even parity for LRC and odd

Parity for VRC): D A T A sp C O M M U N I C A T I O N S (8M+7M)

8. a) Explain about Digital and Channel Service Units. Also distinguish between them.

b) Explain in detail about various classifications of Voice-Band Modems. (8M+7M)

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Code No: R22121


DATA COMMUNICATION





~~~~~~~~~~~~~~~~~~~~~~

1. a) Explain in detail about Layered Network Architecture.

b) Explain in detail about Non-Sinusoidal, complex wave and list properties of these complex

waves. (8M+7M)

2. a) Define Transverse Electromagnetic waves. What are the characteristics of electro-magnetic

waves?

b) Explain about the Optical Fiber Modes and give their classifications. Also give advantages

and disadvantages of each Optical Fiber Mode. (8M+7M)

3. a) Differentiate between Delta Modulation PCM and Differential PCM.

b) Explain in detail about Wavelength-Division Multiplexing. (8M+7M)

4. a) Explain briefly about Spherical Wave front and the Inverse Square Law.

b) Describe in detail about Terrestrial Propagation of Electromagnetic Waves. (8M+7M)

5. a) Explain about Cordless Telephones and Electronic Telephones.

b) Define Crosstalk. Explain in detail about Private-Line Circuits. (8M+7M)

6. a) Explain about Personal Communication System. Give its advantages and disadvantages.

b) Give a brief description about various Network Components. (8M+7M)

7. a) Briefly describe the following error-detection schemes: single-precision checksum, double

precision checksum, Honeywell checksum, residue checksum.

b) Determine the BCC for the following data- and CRC-generating polynomials: (8M+7M)

G(x) = x7+x

4+x

2+x

0

P(x) = x5+x

4+x

1+x

0

8. a) Discuss briefly about Synchronous Voice-Band Modems.

b) Distinguish Voice-Band Modem, 56K Modems and Cable Modems. (8M+7M)

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Code No: R22121


DATA COMMUNICATION





~~~~~~~~~~~~~~~~~~~~~~

1. a) Explain about two-station data communication circuit. Also give a brief description about

parallel and serial data transmission with suitable diagrams. (8M+7M)

b) Explain about Quadrature Amplitude modulation and Trellis Code modulation in detail.

2. a) Define Metallic Transmission Lines. Explain about types of metallic transmission lines.

b) Explain about the Optical Fiber Communications System with a block diagram. (8M+7M)

3. a) Explain briefly about Signal Voltage-to-Quantization Noise Voltage Ratio.

b) Define Carrier Systems and explain in detail about T-Carrier Systems. (8M+7M)

4. a) Explain in detail about Electromagnetic Polarization and Optical properties of radio waves.

b) Explain in detail about Microwave Communication Systems. (8M+7M)

5. a) Define Subscriber Loop. Explain in brief about working of standard Telephone Set.

b) Explain in detail about units of Powers Measurement. (8M+7M)

6. a) Explain about Cell Splitting, Sectoring, Segmentation and Dualization.

b) Explain about the architecture of Global System for Mobile Communications. (8M+7M)

7. a) Explain briefly about Data Communications Character Codes.

b) Explain in detail about Error-Correction mechanisms. (8M+7M)

8. a) Discuss briefly about Asynchronous Voice-Band Modems.

b) Give a detailed description about Cable Modems. (8M+7M)

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Code No: R22025


ELECTRICAL CIRCUIT ANALYSIS -II

(Electrical and Electronics Engineering)




~~~~~~~~~~~~~~~~~~~~~~

1. a) Compare a three phase star connected system with a delta-connected system. Discuss merits

and demerits of the two systems.

b) A star connected load with three equal impedances takes 10 kW at 0.8 power factor leading

when connected to 440 V, three-phase, three-wire supply. Find the line current if one phase of

the load is short-circuited.

2. For the network shown in Fig. 2 calculate the line currents and power consumed if

a) the phase sequence is ABC

b) if the phase sequence ACB.

3. a) A dc voltage of 100V is applied in the circuit shown in fig. 3(a) and the switch is kept open.

The switch K is closed at t = 0. Find the complete expression for the current.

b) A series R-L circuit has R=20 ohms and L=8 H. The circuit is connected across a DC

voltage source of 120 V at t=0. Calculate the time at which the voltage drops across R and L

are the same.

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100 V, 3-phase,

50 Hz

Supply

3+ j4 Ω

A

Fig.2

2- j2 Ω

5 Ω

IA

IB

IC

B

C

20 Ω

t=0

+

Fig.3(a)

0.1 H 100 V -

10 Ω

K

Code No: R22025

4. A series RL circuit with R=100 ohms and L= 1H has a sinusoidal voltage source

)sin(500t 200 φ+ applied at time when 0=φ . i) Find the expression for current ii) At what

value of φ must the switch be closed so that the current directly enter steady state.

5. a) Determine the Y- parameters of the network shown in fig. 5(a).

b) The Z-parameters of a two port network are Z11=15 Ω, Z22=24 Ω, Z12=Z21=6 Ω. Determine

ABCD parameters.

6. Determine the ABCD parameters of the network shown in fig. 6

7. The voltage having the waveform shown in fig. 7.1 is applied to the circuit shown in fig. 7.2.

Determine i(t).

8. Determine the Fourier transform of the triangular function shown in fig. 8.

2 of 2

Fig.6

4Ω

2Ω

4Ω

1Ω

1

11

2

21

4Ω

2Ω

4Ω

1Ω

I1

V1 V2

Vin(t)

A

t 2T T

Fig. 7.1

3T 4T

2F i(t)

Fig. 7.2

3 H

Vin(t) +

- 25Ω

f(t)

A

t T/2 -T/2

Fig. 8

R10 SET - 1

Fig.5(a)

3Ω

6Ω

3Ω

6Ω

3Ω

6Ω

Code No: R22025







~~~~~~~~~~~~~~~~~~~~~~

1. a) Explain how the reactive power is measured in a 3-phase balanced system.

b) A balanced three-phase star connected load 210 kW takes a leading current of 160 A when

connected across a symmetrical 1.1 kV, 50 Hz supply. Find the load circuit passive parameters

per phase.

2. The following impedances are connected in the form of a star connected unbalanced system

and it is connected to a 400 V, 3-phase supply: , 30 Ω= jZ R , 3 Ω= jZY . 3 Ω−= jZ B

Calculate the line currents by using i) loop method ii) Star-delta transformation technique.

3. In the circuit shown in fig. 3, switch S1 is closed at t=0 and S2 is opened at t=0.05 sec. Find the

transient current. Use differential equation approach.

4. Find the current in the circuit shown in fig. 4 for t>0. At t=0- the network was unenergized.

5. a) Express z-parameters in terms of h-parameters and ABCD-parameters.

b) The y-parameters of a two port network are y11=15 mho, y22=24 mho, y12=y21=6 mho.

Determine ABCD parameters.

1 of 2

1 H

10 sin2t ~

1 F

1Ω

Fig.4

t=0

R10 SET - 2

50 Ω

S2

Fig.3

5 H 200 V

+

-

100 Ω

S1

Code No: R22025

6. Determine the y-parameters for the two port network shown in fig. 6.

7. a) Determine the Fourier series of the repetitive waveform shown in fig. (7.1) up to the 7th

harmonic when the repetition time T=25π ms.

b) Determine the fundamental frequency current in the circuit shown in fig. (7.2), where R=15

ohms and L=0.0438 H with the voltage waveform given in fig. (7.1).

8. Determine the Fourier transform of the trapezoidal function shown in fig. 8.

2 of 2

Fig.6

j4 S 2 S 3 S

4 S

-j2 S -j6 S

Fig. (7.2)

v(t)

t 0

Fig. (7.1)

-150 V

150 V

T/2

T

R L

v(t)

f(t)

A

t b a -a -b

Fig. 8

R10 SET - 2

Code No: R22025







~~~~~~~~~~~~~~~~~~~~~~

1. Two wattmeters A and B give readings as 5000 W and 1000 W respectively of the power

measurement in a 3-phase, three wire balanced load system.

a) Calculate the power and power factor when both of them read in i) direct and ii) reverse if

the voltage of the circuit is 400 V.

b) What is the value of the capacitance which must be introduced in each phase so that the

whole of the power will appear on wattmeter A? The frequency of the supply is 50 Hz.

2. a) Explain how the three-phase power is measured using two-wattmeter method.

b) Find the reading on the wattmeter when the network is connected to a symmetrical three

phase, 440 V, supply as shown in fig. 2b. Neglect the electrostatic effects and instrument

losses. The phase sequence is ABC.

3. In a series RLC circuit, R=6 ohms, L=1 H, C=1 F. A DC voltage of 40 V is applied at t=0.

Obtain the expression for i(t) using differential equation approach.

4. For an RC series circuit, a sinusoidal voltage tsin)( ωmVtv = is applied at t=0. Find the

expression for transient current.

1 of 2

R10 SET - 3

45 Ω

A

Fig.2b

56 Ω 60 Ω V1

IB

M

B

C

L

V2

IC

IA

Code No: R22025

5. a) Express y-parameters in terms of z-parameters and h-parameters

b) Determine ABCD parameters of the network shown in fig. 5(b).

6. Find the y-parameters for the network shown in fig. 6 by considering it to be a parallel

combination of a capacitive network referred to as Na and a resistive network referred to as Nb.

7. a) The input voltage in volts to a series RL is

18 )35sin(942t 56 )10sin(314t 180)( 00 ++++=te The values of R and L are 18Ω and 0.0413

H. Determine

i) The expression for current,

ii) The rms value of voltage and current, and

iii) the power factor of the circuit.

b) Explain about the exponential Fourier series.

8. Determine the Fourier transform of the function shown in fig. 8.

2 of 2

21

Fig.5(b)

1 H

1 F

2 H

0.5 F

1

11

2

Fig.6

2Ω

-j1Ω

1Ω

1Ω

R10 SET - 3

f(t) A

t T

-T

-A

0

Fig.8

Code No: R22025







~~~~~~~~~~~~~~~~~~~~~~

1. a) Explain the relationship between line and phase quantities in a star and delta connected three

phase systems.

b) Each phase of a three-phase delta connected load has a 0.2 H inductor in series with a

parallel combination of an 8 µF capacitor and a 100 Ω resistor. If a three phase voltage of 200

V at a frequency of 400 rad/sec is applied to this load, find i) the phase current ii) the line

current iii) the total power absorbed by the load.

2. A balanced three phase, three wire 50 Hz, 100 V supply is given to a load consisting of three

impedances ZA=(1+j1), ZB=(1+j2) and ZC=(3+j4) ohms connected in star as shown in fig. 2.

Compute the voltage across and currents in the three phases of the load using i) Millman’s

theorem ii) loop current method. Phase sequence is ABC.

3. In the circuit shown in figure 3, the switch S is in position 1 for 0.01 seconds and then changed

to position 2. Find the time at which the current is zero and reversing its direction.

1 of 2

Fig.2

N

IB

120100 −∠=BnV

B +

120100∠=CnV

C +

0100∠=AnV

A + ZA

ZB

ZC IC

IA

N1

I1

I2

R10 SET - 4

5Ω

Fig.3

0.1 H 100 V

+

- +

-

S1

2

20 V

Code No: R22025

4. For an RL series circuit, a sinusoidal voltage of )tsin()( φω += mVtv is applied at t=0. Find the

expression for transient current.

5. Determine the Z-parameters for the network shown in fig. 5

6. Derive the ABCD parameters for the network shown in fig. 6 as a cascade connection of two

identical networks.

7. a) The current in an RL circuit with R=12Ω and sin(4500t) sin(2700t) 7 sin(900t) 12)t(i ++= .

Determine the effective applied voltage and average power.

b) Obtain the trigonometric Fourier series for the waveform shown in fig. 7.b.

8. a) Explain the properties and applications of Fourier transform.

b) Find the Fourier transform of the signal )sin()( 0ttf ω= .

2 of 2

V2 Port 2

Fig.5

1Ω

2Ω

1Ω

4V1 1Ω + -

1

11

2

21

Port 1 V1

2Ω

V1

21

Fig.6

2 Ω

1 F

4 Ω

1 F

1

11

2

V2

Vin(t)

A

t T T/2

Fig. 7.b

0

R10 SET - 4

Code No: R22051


SOFTWARE ENGINEERING

(Computer Science and Engineering)




~~~~~~~~~~~~~~~~~~~~~~

1. Define the terms “Software” and “Software Engineering”. State and explain various software

myths and reality.

2. Compare the waterfall model with the Unified process. And also list out various categories of

non-functional requirements and their importance.

3. What is meant by requirements management? Discuss in detail about requirements

management and requirements validation.

4. Explain various architectural styles and patterns. And also explain about architectural design.

5. Discuss the advantages of Object–Oriented design over other design methods. Explain the

process of user interface design evaluation.

6. Define the term software quality. And explain the metrics for design model and metrics for

source code.

7. Distinguish between software Measurement and Metrics. And also discuss in detail the

proactive strategies of risk management.

8. Discuss the necessity for software quality assurance. And explain about the statistical software

quality assurance.

1 of 1

R10 SET - 1

Code No: R22051







~~~~~~~~~~~~~~~~~~~~~~

1. Distinguish between software process and software project. Explain about personal and team

process models.

2. Differentiate between Incremental process models and Evolutionary process models. And also

discuss various topics in a software requirements specification document.

3. Explain the requirements validation process in detail. And also discuss about data models and

object models with suitable examples.

4. Discuss the importance of design phase in software development. And also explain various

software design concepts with suitable examples.

5. Explain in detail with a suitable example the Object-Oriented design process.

6. State and explain various testing methods under white-box and black-box testing.

7. What is the need for risk management? Explain the process of risk identification, risk

projection and risk refinement.

8. What are the formal technical reviews? Explain them. And also discuss about the ISO 9000

quality standards.

1 of 1

R10 SET - 2

Code No: R22051







~~~~~~~~~~~~~~~~~~~~~~

1. Discuss the changing nature of the software. And also explain about process patterns and

CMMI.

2. Distinguish between functional and non-functional requirements. And compare the waterfall

model with the Evolutionary process models.

3. Discuss the importance of system models. And also state and explain various techniques for

requirements elicitation and analysis.

4. Distinguish between data design and architectural design. And also explain the design

principles for design quality.

5. What are factors that will influence on a user interface design? Explain clearly about user

interface analysis and design.

6. What is the need for validation testing? Discuss it with suitable examples. And also discuss the

metrics for software testing.

7. What are the benefits of software measurement? Discuss in detail the RMMM Plan with a

suitable example.

8. State and explain various software quality assurance activities. And discuss how we measure

software reliability.

1 of 1

R10 SET - 3

Code No: R22051







~~~~~~~~~~~~~~~~~~~~~~

1. Discuss the Evolving role of software and CMMI. And also compare the personal and team

process models.

2. Explain with suitable examples the user requirements, system requirements and non-functional

requirements.

3. What is meant by feasibility study? State and explain various feasibility studies that may be

performed on a software project. And also discuss about context models.

4. What is meant by architectural design? Discuss its significance. And also explain various

terminologies in software architecture.

5. Describe the golden rules for a user interface design. Explain the interface design steps.

6. What are the testing strategies for conventional software? Explain them in detail.

7. Explain various categories of software risks. Explain the risk identification and risk projection

activities.

8. Explain about statistical software quality assurance and software quality standards.

1 of 1

R10 SET - 4

Code No: V0121

II B.Tech II Semester, Supplementary Examinations, April – 2012

PROBABILITY AND STATISTICS

(Com.to CE, ME, CHEM, AME, MM)




*********

1. a) The students in a class are selected at random, one after another, for an examination. Find

the probability P that the boys and girls in the class arranged alternately if

i) the class consists of 4 boys and 3 girls

ii) the class consists of 3 boys and 3 girls

b) In a certain college, 40%of men and 10% of women are taller than1.8 metres. Further

more in the college 60% of students are women. If a student is selected at random and is

taller than 1.8 metres find the probability that the selected student is a woman.

2. A discrete random variable X has the following distribution function :

≥

<≤

<≤

<≤

<

=

10,1

106,6/5

64,2/1

41,3/1

1,0

)(

forx

xfor

xfor

xfor

forx

xF

Find i) )62( ≤< XP ii) )5( =XP iii) )4( =XP iv) )6( ≤XP v) )6( =XP

3. a) six dice are thrown 729 times. How many times do you except at least three dice to show

a 5 or 6

b) Estimate the minimum marks a student must get in order to receive an ‘A’ grade if the top

10% of the students are awarded ‘A’ grade in an examination where the mean of the marks

is 72 and standard deviation is 9.

4. a) A random sample of size 64 is taken from a normal population with

µ =51.4 and σ =68.What is the probability that the mean of the sample will

i) exceed 52.9

ii) fall between 50.5 and 52.3

iii) be less than 50.6.

b) The claim that the variance of a normal population is 42 =σ is to be rejected if the

variance of a random sample of size 9exceeds 7, 7535. What is the probability that this

claim will be rejected even though 42 =σ ?

1 of 2

R07 SET - 1

Code No: V0121

5. a) In a study of an automobile insurance a random sample of 80 body repair costs had a

mean of Rs.472.36 and the S.D of Rs.62.35.If X

is used as a point estimate to the true

average repair costs, with what confidence we can assert that the maximum error doesn’t

exceed Rs.10?

b) Calculate 11,σµ for the posterior distribution if the random sample size is 80.

55.5,85.18 == SX using S.D of population .σ

6. a) Random samples of 400 men and 600 women were asked whether they would like to have

a flyover near their residence.200 men and 325 women were in favour of the proposal .Test

the hypothesis that proportions of men and women in favour of the proposal are same, at 5%

level.

b) An investigation of the relative merits of two kinds of flash light batteries showed that a

random sample of 100 batteries of brand A tested on the average 36.5 hrs with a S.D. of 1.8

hrs while a random sample of 80 batteries of brand B tested on the average 36.8 hrs with a

S.D. of 1.5 hrs. Use a level of significance of 0.05 to test whether the observed difference

between the average life times is significant.

7. a) The average breaking strength of the steel rods is specified to be 18.5 thousand pounds.

To test this sample of 14 rods was tested. The mean and standard deviations obtained were

17.85 and 1.955 respectively. Is the result of experiment significant?

b) 1000 students at college level were graded according to their 1.Q and the economic

conditions of their homes. Use x2 test to find out whether there is any association between

economic conditions at home and 1.Q

1.Q

Economic conditions High Low Total

Rich 460 140 600

Poor 240 160 400

Total 700 300 1000

8. Customers arrive at a one window drive-in bank according to a Poisson distribution with

mean 10 per hour. Service time per customer is exponential with mean 5 minutes. The car

space in front of the window including that for the serviced can accommodate a maximum

of 3 cars. Other cars can wait outside the space.

a) What is the probability that an arriving customer can drive directly to the space in front of

the window?

b)What is the probability that an arriving customer will have to wait outside the indicated

space?

c) How long is and arriving customer expected to wait before starting service.

2 of 2

R07 SET - 1

Code No: V0121







*********

1. a) Six boys and six girls sit in a row at random. What is the probability that

i) the six girls sit together

ii) the boys and girls sit alternately

b) A husband and wife appear in an interview for the same post .The probability of

husband’s selection is 1/7 and that of wife’s selection is 1/5. What is the probability that

i) both of them will be selected

ii) none of them will be selected

iii) only one of them will be selected.

2. a) From a lot of 10 items containing 3 defectives, a sample of 4 items is drawn a random.

Let the random variable X denote the number of defective items in the sample. Find the

probability distribution of X when the sample is drawn without replacement.

b) X is a continuous random variable with probability density function given by

>><<−

=−−

otherwiseo

xforxkxxf

,

0.0.10,)1()(

11 βαβα

3. a) Adie is thrown 6 times. If getting an even number is a success, find the probabilities of

i) at least one success

ii) 3≤ successes

iii) 4 success.

b) It has been claimed that in 60% of all solar heat installations the utility bill is reduced by

at least one-third. Accordingly, what are the probabilities that the utility bill will be reduced

by at least one –third in

i) four of five installations

ii) at least four of five installations

4. a) The mean height of students in a college is 155 cms and standard deviation is 15.What is

the probability that the mean height of 36 students is less than 157 cms.

b) A random sample of size 64 is taken from a normal population with µ =51.4 and σ

=68.What is the probability that the mean of the sample will

i) exceed 52.9

ii) fall between 50.5 and 52.3

iii) be less than 50.6.

1 of 2

R07 SET - 2

Code No: V0121

5. a) In a study of an automobile insurance a random sample of 80 body repair costs had a

mean of Rs.472.36 and the S.D of Rs.62.35.If X

is used as a point estimate to the true

average repair costs, with what confidence we can assert that the maximum error doesn’t

exceed Rs.10?

b) What is the maximum error one can expect to make with probability 0.90 when using the

mean of a random sample of size n= 64 to estimate the mean of population with .56.22 =σ

6. a) In a big city 325 men out of 600 men were found to be smokers. Does this information

support the conclusion that the majority of men in this city are smokers?

b) Random samples of 400 men and 600 women were asked whether they would like to

have a flyover near their residence.200 men and 325 women were in favour of the proposal

.Test the hypothesis that proportions of men and women in favour of the proposal are same,

at 5% level.

7. a) A sample of 26 bulbs gives a mean life of 990 hours with a S.D. of 20 hours. The

manufacturer claims that the mean life of bulbs is 1000 hours. Is the sample not up to the

standard?

b) The mean life time of a sample of 25 fluorescent light bulbs produced by a company is

computed to be 157 hours with a S.D. of 120 hours. The company claims that the average

life of the bulbs produced by the company is 1600 hours using the level of significance of

0.05. Is the claim acceptable?

8. a) Explain briefly the main characteristics of queuing system.

b) A TV repair man finds that the time spent on his jobs has an exponential distribution

with mean 30 minutes. He repairs sets in the order in which they arrive. The arrival of the

sets is approximately poisons with an average of10 per an eight hour day. Find the

repairman’s idle time each day. How many jobs are ahead of the average set just brought in?

2 of 2

R07 SET - 2

Code No: V0121







*********

1. a) Six boys and six girls sit in a row at random. What is the probability that

i) the six girls sit together

ii) the boys and girls sit alternately

b) A test of multiple choice questions with four choices is held. A candidate appearing for

the test either guesses or recalls or computes the answer for any question. The probability

that he makes a guess is 1/6 and the probability that he recalls the answer is 1/3.The

pro0bability that his answer is correct, given that he recalls it is 1/8.Find the probability that

he computes the answer to the question, given that he answered it correctly.

2. a) From a lot of 10 items containing 3 defectives, a sample of 4 items is drawn a random.

Let the random variable X denote the number of defective items in the sample. Find the

probability distribution of X when the sample is drawn without replacement.

b) The probability density function of a variate X is as follows:

X 0 1 2 3 4 5 6

P(X) K 3K 5K 7K 9K 11K 13K

i) Find P(X<4), )63(),5( ≤<≥ XPXP

3. a) Find the probability that at most 5 defective components will be found in a lot of

200.Experilence shows that 2% of such components are defective. Also find the probability

of more than five defective components.

b) A box contains 100 transistors,20 of which are3 defective and 10 are selected at random,

find the probability that

i) all re defective

ii) at least one is defective

iii) all are good

iv)at most 3 are defective

4. a) The average cost of a studio condominium in the cedar lakes development is Rs.62,000

and the S.D is Rs.4200 .What is the probability that a condominium in this development will

cost at least Rs.65,000.

b) The claim that the variance of a normal population is σ 2=21.3 is rejected if the variance

of a random sample of size 15 exceeds 39.74. What is the probability that the claim will be

rejected even though σ 2=21.3?

1 of 2

R07 SET - 3

Code No: V0121

5. a) It is desired to estimate the mean time of continuous use until an answering machine will

first require service. If it can be assumed that 60=σ days, how large a sample is needed so

that one will be able to assert with 90% confidence that the sample mean is off by at most 10

days.

b) A professor’s feelings about the mean mark in the final examination in “probability” of a

large group of students is expressed subjectively by normal distribution with

.5.12.670 == σµ and

6. a) In two large populations, there are 30%,and 25% respectively of fair haired people. Is this

difference likely to be hidden in samples of 1200 and 900 respectively from the two

populations?

b) In a survey of buying habits, 400 women shoppers are chosen at random in super market

‘A’ located in a certain section of the city. Their average weekly food expenditure is Rs.250

with a S.D of Rs.40.For 400 women shoppers chosen at random in super market ‘B’ in

another section of the city, the average weekly food expenditure is Rs220 with a S.D.of

Rs.55.Test at 10% level of significance whether the average weekly food expenditure of the

two populations of shoppers are equal.

7. a) The average breaking strength of the steel rods is specified to be 18.5 thousand pounds.

To test this sample of 14 rods was tested. The mean and standard deviations obtained were

17.85 and 1.955 respectively. Is the result of experiment significant?

b) From the following data, find whether there is any significant liking in the habit of taking

soft drinks among the categories of employees

Soft Drinks Clerks Teachers Officers

Pepsi

Thumsup

Fanta

10

15

50

25

30

60

65

65

30

8. A toll gate is operated on a freeway where cars arrive according to a Poisson distribution

with mean frequency of 1.2 cars per minute. The time of completing payment follows an

exponential distribution with mean of20 seconds. Find

i) The idle time of the counter

ii) Average number of cars in the system

iii) Average number of cars in the queue

iv) Average time that a car spends in the system

v) Average time that a car spends in the queue.

vi) The probability that a car spends more than 30 seconds in the system.

2 of 2

R07 SET - 3

Code No: V0121







*********

1. a) A can hit a target 3 times in 5 shots, B hits target 2 times in 5 shots ,C hits target 3 times

in 4 shots. Find the probability of the target being hit when all of them try.

b) Suppose three companies X,Y,Z produce T.V’s X produce twice as many as Y While Y

and Z produce the same number .It is known that 2% of X,2% of Y and 4% of Y are

defective. All the T.V’s produced and put into one shop and then one T.V. is chosen at

random

i)What is the probability that the T.V is defective ?

ii)suppose a T.V chosen is defective, what is the probability that this T.V is produced by

company X ?

2. a) A random variable gives measurements X between 0 and 1 with a probability function

≤≤+−

=elsewhere

xforxxxxF

,0

10,102112)(

23

i) Find )2

1( ≤XP and )

2

1( >XP

ii) Find a number K such that 2

1)( =≤ KXP

b) If the probability density function of random variable X is given by

≤

>=

−

0,0

0,2)(

2

forx

forxkxexF

x

Determine

i) k

ii) the distribution function for X

3. a) six dice are thrown 729 times. How many times do you except at least three dice to show

a 5 or 6

b) Find the probability that out of 100 patients between 84 and 95 inclusive will survive a

heart –operation given that the chance of survival is 0.9.

4. a) The guaranteed average life of a certain type of electric bulbs is 1500 hrs with a S.D of

120 hrs. It is decide to sample the output so as to ensure that 95% of bulbs do not fall short

of the guaranteed average by more than 2%.What will be the minimum sample size.

b) The claim that the variance of a normal population is 42 =σ is to be rejected if the

variance of a random sample of size 9exceeds 7,7535. What is the probability that this claim

will be rejected even though 42 =σ ?

1 of 2

R07 SET - 4

Code No: V0121

5. a) A random sample of 20 fuses subjected to overload has mean time for blow of 10.63

minutes with S.D of 2.48 mt. What can we assert with 95% confidence about the maximum

error if we use X =10.63 mts as a point estimate of true average it takes such fuses for blow

when subjected to overload.

b) Calculate 11,σµ for the posterior distribution if the random sample size is 80.

55.5,85.18 == SX using S.D of population .σ

6. a) A sample of 900 members has a mean of 3.4 cms and S.D 2.61 cms. Is the sample from a

large population of mean 3.25 cm and S.D 2.61 cms. If the population is normal and its

mean is unknown find the 95% fiducial limits of true mean.

b) An investigation of the relative merits of two kinds of flash light batteries showed that a

random sample of 100 batteries of brand A tested on the average 36.5 hrs with a S.D. of 1.8

hrs while a random sample of 80 batteries of brand B tested on the average 36.8 hrs with a

S.D. of 1.5 hrs. Use a level of significance of 0.05 to test whether the observed difference

between the average life times is significant.

7. a) A random sample of size 16 values from a normal population showed a mean of 53 and a

sum of squares of deviation from the mean equals to 150.Cand this sample be regarded as

taken from the population having56 as mean ?. Obtain 95% confidence limits of the mean of

the population.

b) 12 dice were thrown 4096 times and a throw of 6 was reckoned as success. The observed

frequencies were as given below.

Success 0 1 2 3 4 5 6 7 and over

Frequencies 447 1145 118 796 380 115 24 8

Find the value of x2 on the hypothesis that the dice were unbiased and hence show that the

data are consistent with this hypothesis so far as the x2 test is concerned.

8. The mean rate of arrival of planes at an airport during the peak period is 20 hours. The

number of arrivals in any hour follows a Poisson distribution. When there is congestion the

planes are forced to fly over the field in the stack awaiting the landing of other planes that

arrived earlier.60 planes per hour can land in good weather and 30 planes per hour can land

in bad weather.

i) How many planes would be flying over the field in the stack on an average in good

weather and in bad weather?

ii) How long a plane would be in the stack in the process of landing in good and bad

weather?

2 of 2

R07 SET - 4

Code No: T0221

II B.Tech II Semester, Supplementary Examinations, April - 2012

POWER SYSTEMS-I


Time: 3 hours Max Marks: 80


All Questions carry Equal Marks **************

1. a) What are the factors to be considered for selection of the static for a thermal power

station?

b) A steam power station has an overall efficiency of 20% and 0.6Kg of coal is burnt per

KWh of electrical energy generated. Calculate the calorific value of fuel.

2. a) What are the methods of producing nuclear reaction? What is chain reaction?

b) Explain the working of a Gas turbine plant with a schematic diagram?

3. a) How are distributions systems classified?

b) Discuss the relative merits and demerits of underground and overhead systems.

4. a) Describe briefly how you will solve AC distribution problems.

b) A single phase distributor one km long has resistance and reactance per conductor of 0.1

ohm and 0.15 ohm respectively. At the far end, the voltage VB=200V and the current is 100

A at a p.f of 0.8lagging. At the mid-point M of the distributor, a current of 100 A is tapped

at a p.f. of 0.6 lagging with reference to the voltage VM at the mid-point . Calculate

i) voltage at mid-point

ii) sending end voltage VA

5. a).What is sub-station? Name the factors that should be taken care of while designing and

erecting a substation.

b) State the advantages of out-door sub-stations over in-door sub-stations.

6. a) Explain the causes of low power factor of the supply system?

b) Discuss the importance of voltage control in the modern power system.

7. a) What do you understand by the load curve? What information’s are conveyed by a load

curve?

b) A generating station has a connected load of 43MW and a maximum demand of 20MW.

The unit generated being 615x106 per annum. Calculate (i) demand factor (ii) load factor.

8. Write short notes on

a) Simple tariff

b) Flat rate tariff

c) Three part tariff

1 of 1

SET - 1 R07

Code No: T0221


POWER SYSTEMS-I





1. Briefly describe the main parts and the working of a steam power station with a neat sketch.

2. Draw the schematic diagram of a nuclear power station and discuss its operation.

3. a) Derive an expression for the voltage drop for a uniformly loaded distributor fed at one

end.

b) How does AC distribution differs from D.C distribution.

4. a) What is the importance of load power factors in AC distribution system?

b) A 500 m long single-phase A.C. distributor has a total impedance of (0.02+j0.04) ohm

and is fed from one end at 240V. It is loaded as follows: 50A at unity power factor, 200m

from feeding point; 100A at 0.8 p.f. lagging, 300m from feeding point; 50A at 0.06 p.f.

lagging at the far end.

Calculate:

i) Total voltage drop

ii) Voltage at the far end.

5. a) Discuss the different types of gas insulated sub-stations.

b) What are the considerations for the selection of site for an out-door sub-station.

6. a) Discuss the disadvantages of a low power factor?

b) What are the various methods of voltage control in a power system?

7. Define and explain importance of the following

a) Connected load

b) Maximum load

c) Demand factor

8. a) Describe the desirable characte5ristics of a tariff?

b) What is mean by power factor tariff? What are its types?

1 of 1

R07 SET - 2

Code No: T0221


POWER SYSTEMS-I





1. a) What are the advantages and disadvantages of a thermal power station?

b) How the coal is utilized in power generation? Describe how it is handled starting from

delivery of coal to final combustion stage.

2. a) Discuss the advantages and disadvantages of Nuclear power station

b) What are factors to be considered for the selection of site of a nuclear power station?

3. a) State the main types of distribution systems used and compare their applications.

b) What are the requirement s of a distribution system.

4. a) Draw the phasor diagram of AC distributor power factor with respect to receiving end.

b) A single phase AC distributor AB 300 meters long is fed from end A and is loaded as

under:

i) 100A at 0.707 p.f. lagging 200 m from point A

ii) 200A at 0.8 p.f. lagging 300 m from point A

iii) The load resistance and reactance of the distributor is 0.2 ohm and 0.1 ohm per

kilometer. Calculate the total voltage drop in the distributor. The load power factors refer to

the voltage at the far end.

5. a) Give the comparison of out-door sub-stations and in-door sub-stations.

b) What ate advantages of Gas insulated sub-stations?

6. a) Discuss the various methods for power factor improvement?

b) Explain with a neat sketch on-load tap changing transformer.

7. Explain briefly

a) Load duration curve

b) Load curve

c) Plant use factor.

8. Describe some of the important types of tariffs commonly used?

1 of 1

R07 SET - 3

Code No: T0221


POWER SYSTEMS-I





1. a) What are the functions of economizer and super heater in a thermal power plant?

b) A thermal power stations ha the following data:

Max. Demand =20,000KW : Load factor =40%

Boiler efficiency=85% : Turbine efficiency =90%

Coal consumption=0.9Kg/KWh : Cost of 1 ton of coal=Rs.300

Determine i) thermal efficiency and ii) coal bill per annum.

2. What are the basic components of nuclear reactor? Explain the function of each

component.

3. a) Give the comparison between over head system and underground system.

b) Write short notes on Ring main distributer.

4. a) What is the method of calculations in A.C. distribution?

b) A single phase distributor 2kilometers long supplies a load of 120 A at 0.8 p.f. lagging

at its far end and a load of 80 A at 0.9 p.f. lagging at its mid-point. Both power factors are

referred to the voltage at the far end. The resistance and reactance per Km (go and return)

are 0.05ohm and 0.1 ohm respectively. If the voltage at the far end is maintained at 230V,

calculate the voltage at sending end.

5. What are the different types of bus-bar arrangements used in sub-stations? Illustrate your

answer with suitable diagram.

6. a) Derive an expression for the most economized value of power factor which may be

attained by a consumer.

b) Explain the purpose of Booste5r transformer? What are its limitations?

7. Define the following

a) Diversity factor b) Utilization factor c) Load factor.

8. a) What do you understand by tariff? Discuss the objectives of tariff.

b) What is mean by two-part tariff? What are the advantages and disadvantages of two-

part tariff?

1 of 1

R07 SET - 4

Code No: T1021/R07 Set No. 1

II B.Tech II Semester Supplementary Examinations, Apr/May 2012CALIBRATION AND ELECTRONIC MEASUREMENTS

(Electronics & Instrumentation Engineering)Time: 3 hours Max Marks: 80

Answer any FIVE QuestionsAll Questions carry equal marks

? ? ? ? ?

1. The table given below lists a sample of experimental data:

Voltage 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11Frequency of 1 3 6 8 10 7 8 4 3 0 1

occurence

Calculate

(a) the arithmetic mean

(b) the deviation from the mean

(c) Standard deviation

(d) Variance

(e) Probable error of one reading

(f) Probable error of mean

(g) Standard deviation of the mean

(h) Standard deviation of standard deviation [16]

2. Write short notes on any THREE standards

(a) Resistance

(b) Voltage

(c) Current

(d) Capacitance [16]

3. (a) Explain the following terms

i. Measurement and test equipment

ii. Traceability

iii. Reliability

iv. Tolerance limits

(b) Explain the procedure that should be followed before attempting to calibratedeflecting instruments? [8+8]

4. (a) Explain the successive approximation type DVM?

1 of 2


(b) Distinguish between series and shunt type ohmmeter from the dial calibration?How can you estimate the internal resistance of an ohmmeter from its dial?

[8+8]

5. (a) Explain the principle and working of Q meter?

(b) To check the distributed capacitance of a coil, the coil is resonated at 10MHz with 120 pF and then is resonated at 15 MHz with 40 pF. What is theinductance of the coil and what is the equivalent distributed capacitance.

[8+8]

6. (a) What is the function of a gate control Flip-Flop in a frequency counter? Ex-plain its operation.

(b) Explain how do you interface the seven-segment display to a counter. [8+8]

7. (a) Explain the operation of 10 to 1 probe .

(b) A given oscilloscope has an input resistance of 10 M ohm shunted by 20 pf.Design a 10 to 1 probe. [8+8]

8. (a) Draw and discuss the spectral displays of various modulations using spectrumanalyzer.

(b) Explain the F M method of magnetic tape recording and explain its advantagesand disadvantages. [8+6+2]

? ? ? ? ?

2 of 2





? ? ? ? ?

1. The table given below lists a sample of experimental data:

Value 3 4 5 6 7 8 9 10 11Frequency of occurence 1 2 3 6 7 6 4 2 1

Calculate

(a) the arithmetic mean

(b) the deviation from the mean

(c) Standard deviation

(d) Variance

(e) Probable error of one reading

(f) Probable error of mean

(g) Standard deviation of the mean

(h) Standard deviation of standard deviation [16]

2. (a) Distinguish between International and absolute standards.

(b) What are the international standards of length and volume?

(c) Write short notes on concept of inductance standards? [5+5+6]

3. (a) Write short notes on how the calibration records are maintained?

(b) Define the following terms :

i. Accuracy

ii. Bias

iii. Calibration

iv. Calibration interval

v. Measurement and testing equipment

vi. Traceability [4+12]

4. Explain the working of multimeters with a neat block diagram? [16]

5. (a) Derive an expression for balance in an Anderson’s bridge. Draw the phasordiagram under balance conditions.

(b) List the advantages and disadvantages of Anderson’s bridge. [10+6]

1 of 2


6. (a) With a suitable block diagram explain the operation of digital frequency meter.

(b) Explain gating errors and time base errors. [8+8]

7. (a) Describe the electrostatic focusing system of a CRT.

(b) What is the minimum distance L, that will allow full deflection of 4 cm at theoscilloscope screen with a deflection factor of 100 V/cm and with an acceler-ating potential of 2000 V ? [8+8]

8. (a) Explain the operation of logic timing analyzer and logic state analyzer.

(b) What are the merits and demerits of Magnetic recording? [5+5+6]

? ? ? ? ?

2 of 2





? ? ? ? ?

1. (a) Ratings of two resistors are as shown below.

R1 = 200Ω ± 5%

R2 = 100Ω ± 5% Calculate

i. magnitude of error in each case

ii. the limiting error in ohms and in percent when resistor are connected inseries and

iii. the limiting error in ohms and in percent when the resistor are connectedin parallel

(b) Explain the following terms

i. Probable error of one reading

ii. Probable error of mean

iii. Standard deviation of the mean

iv. Standard deviation of standard deviation [8+8]

2. Write short notes on any THREE standards:

(a) Resistance

(b) Voltage

(c) Current

(d) Capacitance [16]

3. List out different types of calibrations used and discuss each of them briefly? [16]

4. (a) Write short notes on measurement of very large current by thermocouplemethod?

(b) With a neat block diagram explain the microprocessor based ramp type DVM?[8+8]

5. (a) Draw the circuit of a Maxwell?s inductance bridge and derive an expressionfor the unknown inductance. Draw the phasor diagram at balance.

(b) A Maxwell bridge is used to measure an inductive impedance. The bridgeconstants at balance are C1=0.05µF, R1=100KΩ,R2=500Ω and R3=10KΩ.Find Rx and Lx. [8+8]

6. Write short notes on:

1 of 2


(a) Frequency synthesizer

(b) Zero crossing detectors

(c) Wave meters [6+4+6]

7. (a) Give the standard specifications of horizontal amplifier used in a single beamCRO

(b) Explain the spot wheel method for frequency measurement. [8+8]

8. (a) Draw and discuss the spectral displays of various modulations using spectrumanalyzer.

(b) Explain the F M method of magnetic tape recording and explain its advantagesand disadvantages. [8+6+2]

? ? ? ? ?

2 of 2





? ? ? ? ?

1. (a) What are the different types of systematic errors present? Explain each ofthem with an example?

(b) A voltmeter having a sensitivity of 1KΩ/V is connected across an unknownresistance in series with a milli ammeter reading 80V on 150V scale. Whenthe milli ammeter reads 10mA, calculate the

i. Apparent resistance of the unknown resistance

ii. Actual resistance of the unknown resistance

iii. Error due to the loading effect of the voltmeter. [8+8]

2. List the various levels of measurement standards, and discuss the application ofeach classification. [16]

3. (a) Write short notes on how the calibration records are maintained?

(b) Define the following terms :

i. Accuracy

ii. Bias

iii. Calibration


v. Measurement and testing equipment

vi. Traceability [4+12]

4. Draw the block diagram of multimeters and explain its operation? [16]

5. (a) What causes problems for bridges at radio frequencies?

(b) Mention the applications of Wien bridge.

(c) Point out the sources of errors in Q meter. [6+4+6]





1 of 2


8. (a) Draw the block diagram of a filter bank spectrum analyzer and explain itsoperation.

(b) Write short notes on display systems. [3+5+8]

? ? ? ? ?

2 of 2

Code No: V0521



(Com.to CSE, IT, CSS)




*********

1. Define the terms “Software” and “Software Engineering”. State and explain various

software myths and reality.

2. Compare the waterfall model with the Unified process. And also list out various categories

of non-functional requirements and their importance.

3. What is meant by requirements management? Discuss in detail about requirements

management and requirements validation.

4. Explain various architectural styles and patterns. And also explain about architectural

design.

5. Discuss the advantages of Object–Oriented design over other design methods. Explain the

process of user interface design evaluation.

6. Define the term software quality. And explain the metrics for design model and metrics for

source code.

7. Distinguish between software Measurement and Metrics. And also discuss in detail the

proactive strategies of risk management.

8. Discuss the necessity for software quality assurance. And explain about the statistical

software quality assurance.

1 of 1

R07 SET - 1

Code No: V0521







*********

1. Distinguish between software process and software project. Explain about personal and team

process models.

2. Differentiate between Incremental process models and Evolutionary process models. And

also discuss various topics in a software requirements specification document.

3. Explain the requirements validation process in detail. And also discuss about data models

and object models with suitable examples.

4. Discuss the importance of design phase in software development. And also explain various

software design concepts with suitable examples.

5. Explain in detail with a suitable example the Object-Oriented design process.

6. State and explain various testing methods under white-box and black-box testing.

7. What is the need for risk management? Explain the process of risk identification, risk

projection and risk refinement.

8. What are the formal technical reviews? Explain them. And also discuss about the ISO 9000

quality standards.

1 of 1

R07 SET - 2

Code No: V0521







*********

1. Discuss the changing nature of the software. And also explain about process patterns and

CMMI.

2. Distinguish between functional and non-functional requirements. And compare the waterfall

model with the Evolutionary process models.

3. Discuss the importance of system models. And also state and explain various techniques for

requirements elicitation and analysis.

4. Distinguish between data design and architectural design. And also explain the design

principles for design quality.

5. What are factors that will influence on a user interface design? Explain clearly about user

interface analysis and design.

6. What is the need for validation testing? Discuss it with suitable examples. And also discuss

the metrics for software testing.

7. What are the benefits of software measurement? Discuss in detail the RMMM Plan with a

suitable example.

8. State and explain various software quality assurance activities. And discuss how we measure

software reliability.

1 of 1

R07 SET - 3

Code No: V0521







*********

1. Discuss the Evolving role of software and CMMI. And also compare the personal and team

process models.

2. Explain with suitable examples the user requirements, system requirements and non-

functional requirements.

3. What is meant by feasibility study? State and explain various feasibility studies that may be

performed on a software project. And also discuss about context models.

4. What is meant by architectural design? Discuss its significance. And also explain various

terminologies in software architecture.

5. Describe the golden rules for a user interface design. Explain the interface design steps.

6. What are the testing strategies for conventional software? Explain them in detail.

7. Explain various categories of software risks. Explain the risk identification and risk

projection activities.

8. Explain about statistical software quality assurance and software quality standards.

1 of 1

R07 SET - 4

Code No: V0421


PULSE AND DIGITAL CIRCUITS

(Com.to ECE, BME, ECC, ICE)




*********

1. a) Prove that an RC circuit behaves as a reasonably good integrator if RC>>15T, where ‘T’ is the

time period of input waveform . Also show that the output is approximately

)/(cos RCtVm

ωω−

b) The square wave shown in Fig.1.1 is fed to an RC coupling network. Time period of both

positive cycle and negative cycle is same. What are the voltage waveforms across R and

across C if (i) RC is very large, say RC = 10 T, and RC is very small, say RC = 0.1 T.

Fig. 1.1. A square waveform with a DC shift.

2. a) State and explain clamping circuit theorem. Discuss about the practical clamping circuit

with suitable sketches.

b) A rectangular waveform of Vp-p =10 V, with on time T1 = 2 ms, and off time T2 = 20 ms

is applied to the dc restorer circuit. The circuit has source resistance Rs = 0 ohms, diode

forward resistance Rf =10 Ω, cutin voltage Vγ = 0 V, Rr = ∞, R = 500 Ω, C = 0.1µF.

Compute the steady state output waveform. Repeat the same for R = 1M Ω.

3. a) Discuss about transistor switching times with suitable sketches. What are the three important

factors that contribute to the delay time in a transistor? Explain.

b) Derive the expressions for rise time, fall time of a BJT when it is used as an electronic switch.

4. a) Explain the operation of an emitter coupled astable multivibrator circuit.

b) Design a collector coupled monostable multivibrator circuit for the given specifications:

VCC = 8V, VBE = -1V, IC(sat) = 2 mA, period of the quasi stable state is 2.5 µs. hFE(min) = 20,

the ON transistor (Si) has base current which is 50% in excess of minimum base current.

Assume R2 = 2R1, and ICBO = 0. Assume suitable data.

1 of 2

R07 SET - 1

Code No: V0421

5. a) With the help of circuit diagram, explain the principle of operation of a constant current

sweep circuit.

b) Design a transistor bootstrap ramp generator to provide an output amplitude of 12 V over

a time period of 2 ms. The input signal is a negative going pulse with an amplitude of 5 V, a

pulse width of 2 ms and the time interval between pulses is 0.5 ms. The load resistance is 2

kΩ and the ramp is to be linear within 1%. The supply is to be ±15 V. Assume hFE(min) =

80.

6. a) How an astable multivibrator can be synchronized? Illustrate with waveforms.

b) A symmetrical astable multivibrator using Germanium transistors and operating from a

10 V collector supply voltage has a free period of 1ms. Triggering pulses whose spacing is

750 µs are applied to one base through a small capacitor from a high impedance source.

Find the minimum triggering pulse amplitude required to achieve 1:1 synchronization.

Assume that the timing portion of the base waveform is linear.

7. a) With neat diagrams, explain the principle of operation of six diode bidirectional sampling

gate.

b) Describe the operation of chopper amplifier. Give the operation of the transistor as a

chopper switch in ON state and in OFF state.

c) Describe the operation of balanced choppers.

8. Write the following:

a) DTL NAND gate,

b) RTL NOR gate,

c) Prove that NAND and NOR gates are universal gates.

2 of 2

R07 SET - 1

Code No: V0421







*********

1. a) Derive an expression for the output voltage levels under steady state conditions of a low

pass circuit excited by an exponential input.

b) The limited ramp shown in Figure 2.1 is applied to an RC differentiator. Draw to scale,

the output waveform for the cases i) T = RC ii) T = 0.2 RC iii) T = 5RC.

2. a) Draw the circuit diagrams for double ended clipping of a sinusoidal input signal using diodes and

zener diodes. Explain its operation using transfer characteristics of each circuit.

b) Draw the circuit diagram for positive clamper circuit and explain its principle of operation.

3. a) Explain how a transistor can be used as an electronic switch. Compare switching

operation with that of FET.

b) Design a high speed Si transistor switch (connected in CE configuration) for the given

specifications: VCC = 12 V, -VBB = -10V, IC = 8 mA, hFE(min) = 30, and R2 = 3R1. The resistor

R1 is connected between the base of the transistor and the input, and R2 is connected

between base of the transistor and VBB. Assume suitable saturation, cut off voltages for the

given transistor.

4. a) Derive an expression for the gate width of a monostable multivibrator circuit.

b) Design an astable multivibrator to generate a square wave of 2 kHz frequency with a duty

cycle of 35%. The specifications of switching transistors used in the circuit are: Supply

voltage = ±10 V, IC(ON) = 4 mA, hFE = 20, Si transistors. Assume necessary data.

1 of 2

R07 SET - 2

Code No: V0421

5. a) Discuss the advantages of Bootstrap time base generators over the Miller circuit, and

explain the operation of Bootstrap time base generator.

b) Design a sweep circuit using silicon transistor in the CB configuration to generate a 20 V

sweep in a time of 0.1 ms with a slope error not to exceed 0.2%. The circuit uses two supply

voltages. The transistor has α = 0.98, hib = 20 ohms, hrb = 0.4 x 10-3

and hob = 0.5 µ mho.

Use RE = 1.5 KΩ and select reasonable values of VCC, VEE and capacitor C.

6. a) Discuss about synchronization of a sweep circuit with symmetrical signals.

b) How a monostable multivibrator circuit can be used for frequency division? Explain with

suitable sketches.

c) What do you mean by phase delay and phase jitters?

7. a) Illustrate with neat circuit diagram, the operation of unidirectional sampling gate for

multiple inputs.

b) Explain the operation of a two input sampling gate which does not have any loading

effect on control signal.

c) Give the importance of chopper amplifier.

8. Explain the following terms:

a) Realization of AND and OR gates using universal gates,

b) What is the use of Totem pole configuration? Explain its operation with suitable sketches.

Give an example to calculate Fan-out of the circuit.

2 of 2

R07 SET - 2

Code No: V0421







*********

1. a) Design a high pass circuit for three different time constants, low, high and medium.

Assume a 4 kHz square wave with 4Vp-p is applied to the circuit. Draw the output

waveforms for the time constants mentioned above.

b) A square wave whose peak-to-peak amplitude is 2V extends ±1V with respect to ground.

The duration of the positive section is 0.1 sec and that of the negative section is 0.2 sec. If

this waveform is impressed upon an RC integrating circuit whose time constant is 0.2 sec,

what are the steady state maximum and minimum values of the output waveform?

2. a) Explain transfer characteristics of the emitter coupled clipper and derive the necessary

equations.

b) Draw a clamping circuit in which the source resistance Rs of the signal source is taken

into account, and also resistance R is connected across the output. Find the state output

waveform indicating voltage levels for a complete cycle for a square wave input signal

shown in Fig.3.1.

3. a) What are the important parameters to be observed when the transistor is operated as

electronic switch? Explain them.

b) A transistor initially at cutoff with a base to emitter voltage nearly zero, operates with

VCC = 12 V and Rc = 1 KΩ. A positive step input voltage of 10 V is applied through a 10 KΩ

resistance to the base. It is found that the transistor reaches saturation in 0.3 µs. The silicon

transistor has hFE = 30 and a collector transition capacitance of 10 pF. What is the common

emitter gain-bandwidth product of the transistor?

1 of 2

R07 SET - 3

Code No: V0421

4. a) What is Schmitt trigger? With the help of a neat circuit diagram and waveforms, explain

the working of Schmitt trigger?

b) A self biased bistable multivibrator uses silicon transistors with the following

specifications: hFE = 25, VCC = 20V, VBB = 2V, RC =1kΩ, R1 = R2, IC(sat) = 10mA . If VBE(off)

= -1V and the base current of the ON transistor is twice the minimum base current, design

the circuit and show the diagram with appropriate values of the components.

5. a) Discuss about general considerations of Miller and Bootstrap time base generators.

b) Design a free running UJT sweep waveform generator with the sweep amplitude of 6 V.

The sweep interval of the waveform is expected to be 3 ms with negligible retrace interval.

The slope error is 0.75. Determine the values of RB1, RB2, VBB, R, and C in the relaxation

circuit.

6. a) Illustrate the terms ‘Synchronization’ and ‘frequency division’ of a sweep generator.

b) A free running relaxation oscillator has sweep amplitude of 100 V and a period of 1 ms

synchronizing pulses are applied to the device such that breakdown voltage is lowered by 50

V at each pulse. The synchronizing pulse frequency is 4 kHz. What is the amplitude and

frequency of synchronized oscillator waveform?

7. a) With neat diagrams, explain the principle of operation of four diode bidirectional

sampling gate. Compare the performance of the circuit with that of six diode bidirectional

sampling gate.

b) Describe the errors encountered in series sampling and what is the design procedure that

is adopted to minimize these errors.

8. a) With the help of neat circuit diagram and truth table, explain the working of three- input

DTL NAND gate.

b) What do you mean by ‘fan in’ and ‘fan out’? Discuss about the DTL NAND gate circuit

which can improve Fan-out of the gate.

2 of 2

R07 SET - 3

Code No: V0421







*********

1. a) Derive an expression for the output voltage levels under steady state conditions of a low

pass circuit excited by an exponential input.

b) A square wave whose peak-to-peak amplitude is 1V extends ±0.5V with respect to

ground. The duration of the positive section is 0.1 sec and that of the negative section is 0.2

sec. If this waveform is impressed upon an RC differentiating circuit whose time constant is

0.2 sec, what are the steady state maximum and minimum values of the output waveform?

2. a) List out the types of clamping circuits used in the industry. Give the circuit diagram of

each type. Explain the operation of a clamping circuit whose output signal has negative

offset.

b) Design a diode clamper circuit to restore the positive peaks of 1 kHz input signal to a

voltage level equal to 5V. Assume that the diode voltage during forward bias condition is

0.7 V.

3. a) Define rise time, storage time, fall time, and turn off time in the case of transistor as a

switch.

b) Design a common emitter transistor switch operating with two power supplies VCC = 18

V, -VBB = -12 V. The transistor is expected to operate at IC = 8 mA, and IB = 0.75 mA. The

static current gain is 25. Assume Si transistor, and R2 = 5R1.

4. a) Explain the working principle of an emitter coupled monostable multivibrator with neat

sketches.

b) A fixed bias binary uses NPN silicon transistors with hFE = 25. The circuit parameters are

VCC = 10V, VBB = 2V, RC =1kΩ, R1 = 5 kΩ, and R2 = 10 kΩ, VCE(sat) = 0.3V, and VBE(sat) =

0.7V. Verify that one transistor is in cut off and the other one is in saturation. Also find the

steady state values of currents and voltages. What is the maximum value of ICBO tolerated

before the condition is reached where neither transistor is cut off?

1 of 2

R07 SET - 4

Code No: V0421

5. a) A UJT is used as a switch across a sweep capacitor C which is charged through a resistor

R to a maximum voltage supply VBB. Prove that the sweep duration is given by.

P

lnVV

VVRCT

BB

VBB

s

−

−

=

b) With the aid of circuit diagram, explain the operation of constant current sweep generator

using CB configuration and write the expression for slope error.

6. a) Describe the frequency division employing a transistor monostable multivibrator.

b) A UJT sweep circuit operates with a valley voltage of 3 V and a peak voltage of 16 V. A

sinusoidal synchronizing voltage of 2 V peak is applied between bases. The intrinsic stand-

off ratio is 0.5. If the natural frequency of the sweep is 1 kHz, over what range of

synchronization signal frequency will the sweep remain in 1:1 synchronization with the

synchronization signal?

7. a) Sketch circuit of a simple diode bidirectional sampling gate and describe its functioning

with neat waveforms. Obtain the expressions for gain A, and the two minimum control

voltage levels.

b) Discuss about the balance conditions in a bidirectional diode sampling gate.

8. a) Realize two-input TTL NAND gate truth table and explain its operation with suitable

circuit diagram. Which type of NAND gate is immune to noise? Explain its working.

b) With the help of neat circuit diagram and truth table, explain the working of diode logic

AND gate, and RTL AND gate.

2 of 2

R07 SET - 4


II B.Tech II Semester Supplementary Examinations, Apr/May 2012POWER SYSTEMS-I

(Electrical & Electronic Engineering)Time: 3 hours Max Marks: 80


⋆ ⋆ ⋆ ⋆ ⋆

1. (a) What is the difference between fire tube boiler and water tube boiler?

(b) What is super heater? What are its advantages in the thermal station? Howmany types of super heaters are there? What are the differences betweenthem? [6+10]

2. (a) What is the need of nuclear power generation?

(b) What are the merits and demerits of nuclear power plant? [6+10]

3. (a) What are the advantages of a doubly fed distributor over single fed distributor?

(b) Figure 3b shows a ring distributor with inter connector BD. The supply isgiven at point A. The resistances of go and return of various sections areindicated in the figure. Calculate

i. current in the inter connector

ii. voltage drop in the inter connector. [8+8]

Figure 3b

4. (a) Discuss in brief various methods of AC distribution.

(b) A single-phase distributor 2 km long supplies a load of 120 A at 0.8 powerfactor lagging at its far end and a load of 80 A at 0.9 power factor lagging atits midpoint. Both power factors are referred to the voltage at the far end.The impedance per km (go and return) is (0.05+ j0.1) ohms. If the voltageat the far end is maintained at 230 V, determine the following

i. Voltage at the sending end and

ii. Phase angle between the voltages at both the ends. [8+8]

5. (a) What is a substation? Name the factors that should be taken care of whiledesigning and erecting substation.

1 of 2


(b) What is group switching? Explain its operation in detail with help of suitablediagram. [8+8]

6. (a) Explain the function of a synchronous phase modifier placed at the receivingend of the transmission line

(b) A 3 phases 500 H.P, 50 Hz, 11 KV star connected induction motor has a fullload efficiency of 85% at lagging p.f. of 0.75 and is connected to a feeder. Ifit is desired to correct the p.f of 0.9 lagging load. Determine the

i. The size of the capacitor bank in KVAR

ii. The capacitance of each unit if the capacitors are connected in ∆ as wellas in Y. [8+8]

7. (a) Discussion effect of load factor and diversity factor on the cost of generationin a power system.

(b) A power station has a maximum demand of 15MW, a load factor of 70%, aplant capacity factor of 52.5% and a plant use factor of 85%. Find

i. the daily energy produced

ii. the reserve capacity of the plant and

iii. the maximum energy that could be produced daily if the plant were inuse all the time. [8+8]

8. Describe the different types of tariffs. [16]

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⋆ ⋆ ⋆ ⋆ ⋆

1. Draw the schematic diagram of thermal power station and also briefly discuss themain components of the station. [16]

2. Briefly discuss the main parts of a nuclear reaction and explain the principle ofoperation. [16]

3. (a) Discuss briefly the requirements of a distribution system

(b) A 2-wire DC ring distributor is 300m long and is fed at 240V at point A. Atpoint B, 150m from A, a load of 120A is taken and at C, 100m in the oppositedirection, a load of 80a is taken if the resistance per 100m of single conductoris 0.03Ω, find

i. current in each section of distributor

ii. voltage at points B and C. [8+8]

4. A 3-phase distribution system is shown in figure 4 Power is supplied at A at linevoltage of 6.6 kV and balanced loads of 25A per phase at 0.8 lagging p.f and 35Aper phase at 0.9 lagging p.f are taken at B and C respectively. The impedances ofthe feeders are AB = (5 + j9) Ω, BC = (6 + j10)Ω and CA = (4 + j8) Ω. Calculatethe voltage at B and C and the current in each branch p.f.’s are assumed w.r. tovoltage at A. [16]

Figure 4

5. (a) What is a substation? Name the factors that should be taken care of whiledesigning and erecting substation.

(b) What is group switching? Explain its operation in detail with help of suitablediagram. [8+8]

1 of 2


6. (a) Why is excitation control necessary in an alternator?

(b) An industrial load consists of

i. 250 h.p (metric) induction motor having overall power factor 0.8 laggingand efficiency 85%.

ii. 150 h.p. Synchronous motor of efficiency 85% and works at a power factor0.707 lagging. The consumer is charged at the rate of Rs. 75 per kVAof maximum demand plus 3 Paise per kWh. Calculate the annual savingof the synchronous motor, which works at a leading power factor of 0.8.Assume 100 percent load factor. [8+8]

7. (a) Discussion effect of load factor and diversity factor on the cost of generationin a power system.

(b) A power station has a maximum demand of 15MW, a load factor of 70%, aplant capacity factor of 52.5% and a plant use factor of 85%. Find

i. the daily energy produced

ii. the reserve capacity of the plant and

iii. the maximum energy that could be produced daily if the plant were inuse all the time. [8+8]

8. (a) What is the objective of tariff? What type of tariff is employed for domesticconsumers? Why is this tariff not employed for a bulk power consumer?

(b) The fixed costs of a thermal power station are Rs. 500 per KW of installed ca-pacity per year. The fuel and operating costs are 10 paise per KWh generated.Determine the cost of the electrical energy generated per KWh at station loadfactor of 25%, 50%, 75%, 90% and 100%. Comment on the results. [8+8]

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⋆ ⋆ ⋆ ⋆ ⋆

1. Explain the following with block diagram.

(a) Air and flue gas circuit

(b) Feed water - steam flow circuit. [8+8]

2. (a) What are the various ways in which you can classify nuclear reactors?

(b) What are the different safety methods to be applied in the nuclear powerstation? [8+8]

3. (a) Find out the voltage drop expression of a two wire DC distribution with auniformly load being fed at one end.

(b) A 2-wire DC distributor cable AB is 2Km long and supplies loads of 100A,150A, 200A and 50A situated 500m, 1000m, 1600m and 3000m from the feed-ing point A. Each conductor has a resistance of 0.01Ω per 1000m. Calculatethe p.d at each load point if a p.d. of 300V is maintained at point A. [8+8]

4. (a) What are the factors to be considered during the voltage drop calculation inAC distribution.

(b) A single phase, two wire A.C. feeder is loaded as shown in Figure 4b. Thepower factors are lagging and are referred to the voltage at the respective loadpoints. The impedances of section PQ and QR are (0.03 + j 0.05) and (0.05+ j 0.08) ohm respectively. Determine the voltage magnitude and phase angleat the supply end, if the voltage at the far end is 230 V. [8+8]

Figure 4b

5. (a) Explain the construction aspects of gas insulated substations.

(b) What is the difference between air insulated substations and gas insulatedsubstations. [10+6]

6. (a) Why is excitation control necessary in an alternator?

(b) An industrial load consists of

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i. 250 h.p (metric) induction motor having overall power factor 0.8 laggingand efficiency 85%.

ii. 150 h.p. Synchronous motor of efficiency 85% and works at a power factor0.707 lagging. The consumer is charged at the rate of Rs. 75 per kVAof maximum demand plus 3 Paise per kWh. Calculate the annual savingof the synchronous motor, which works at a leading power factor of 0.8.Assume 100 percent load factor. [8+8]

7. (a) Define the terms: annual plant use factor and annual plant capacity factor ofa power station and discuss the effect of these factors on the choice of the sizeand number of units, the reserve capacity of plant and the operating scheduleof the station.

(b) A consumer has the following connected loads: 15 lamps of 40W each and twoheaters of 1,000W each. His maximum demand is 15000W. On the averagehe uses 10 lamps 5 hours a day and each heater for 3 hours a day. Find hisaverage load, monthly energy consumption and load factor. [8+8]

8. (a) Explain with examples :

i. Flat rate tariff

ii. Block rate tariff

iii. Two part tariff

iv. power factor tariff.

(b) A 125 kVA transformer with a copper loss of 1.4 kW at full load an iron lossof 1.2 kW has the following operating schedule per year.Full load at 0.8 p.f. for 2,000 hrsHalf - full load at 0.8. p.f. for 2,500 hrsNo-load for the remaining hours.Find the total annual electricity bill if the flat rate tariff is 60 paise / kWh.

[8+8]

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⋆ ⋆ ⋆ ⋆ ⋆

1. (a) What is economizer? What is its advantages.

(b) Describe the various systems of ash handling methods. [8+8]

2. (a) Discuss briefly the ratio-active pollution of environment by nuclear powerplant.

(b) Describe the different types of fuels used in a nuclear power plant and discussthe problems of nuclear waste disposal. [6+10]

3. (a) Derive an expression for the power loss in a uniformly loaded distributor fedat one end.

(b) The figure 3b show a ring main supplied at point X and loaded at points Aand B. The resistance of the various sections (both go and return) are shown.Find

i. the current in AB section and voltages at load points A and B

ii. the voltage drop between X and A, when load at B is removed. [8+8]

Figure 3b

4. (a) Discuss in brief various methods of AC distribution.

(b) A single-phase distributor 2 km long supplies a load of 120 A at 0.8 powerfactor lagging at its far end and a load of 80 A at 0.9 power factor lagging atits midpoint. Both power factors are referred to the voltage at the far end.The impedance per km (go and return) is (0.05+ j0.1) ohms. If the voltageat the far end is maintained at 230 V, determine the following

i. Voltage at the sending end and

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ii. Phase angle between the voltages at both the ends. [8+8]

5. (a) Explain the main and transfer bus bar system with circuit diagram.

(b) What is the difference between single bus bar with and without sectionalizationarrangement? [8+8]

6. (a) What factors determine the economical limit of p.f. correction? Show thatthe economical limit to which the p.f. of a lagging p.f. load can be raised isindependent of the original value of the p.f. if the tariff consists of a fixedcharge per KVA of maximum demand plus a flat rate per KWh.

(b) Calculate the value of the new p.f. when the tariff is Rs. 1,350 per KVA ofmaximum demand plus a flat rate paise 80 per kWh. Assume additional costof condensers etc. at Rs. 1,050 per KVA of such plant. Rate of interest anddepreciation together is taken as 10%. [8+8]

7. (a) Define the load factor? What is it importance?

(b) A central station supplied energy to two substations A and B, four feeders takeoff from each of the sub-stations the maximum demand are as given belowCentral station : 10MW Feeders on substation A : 1.5, 2, 5, 3 MW

Substation A : 6 MW Feeders on substation B : 2, 4, 5, 1 MW

Substation B : 8 MW

Calculate the diversity factors between

i. substations

ii. feeders on substation A and

iii. Feeders on substation B. [10+6]

8. (a) Explain the simple type of tariff. What are the defects of simple tariff?

(b) A consumer has an annual consumption of 70, 80 KWh, the charge is Rs. 100per kW of maximum demand plus 5 paise per KWh.

i. Find the annual bill and the overall costs per KWh if the load factor is40%.

ii. What is the over all cost per KWh if consumption was reduced by 25%with the same load factor. [8+8]

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? ? ? ? ?

1. Write short notes on any of the FOUR:

(a) Arithmetic mean

(b) Deviation from the mean

(c) Average deviation

(d) Standard deviation

(e) Variance. [16]

2. (a) Write short notes on atomic standards for frequency and time?

(b) State the SI units, unit symbols and define each unit for the following:

i. Voltage

ii. Resistance

iii. Inductance

iv. Capacitance [8+8]

3. (a) Explain the following terms:

i. Accuracy

ii. Bias

iii. Calibration


(b) What are the things involved in calibration program? [8+8]

4. (a) Write short notes on the principle of peak reading voltmeter?

(b) Illustrate the principle and working of ramp type DVM? Compare its perfor-mance with other types of DVM’s? [8+8]

5. (a) Discuss the problems associated in AC bridges if used for measurement at veryhigh frequencies.

(b) A Hay bridge is used to measure an inductive impedance.The bridge constantsat balance are C1=0.1µF, R1= 20KΩ, R2= 5KΩ R3= 2KΩ and W=3000rad/s. Calculate Lx, Rx. [8+8]



1 of 2




8. (a) Compare the selectivity characteristics of the spectrum analyzer and waveanalyzer.

(b) Explain the following terms associated with spectrum analyzer.

i. Sensitivity

ii. Dynamic Range

iii. Harmonic mixing [7+3+3+3]

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? ? ? ? ?


i. Precision

ii. Sensitivity

iii. Resolution

iv. Error

(b) A voltmeter, having a sensitivity of 1000Ω/V, reads 40V on its 150V scalewhen connected across an unknown resistor in series with a milli ammeter.When the milli ammeter reads 800mA, calculate

i. the apparent resistance of the unknown resistor

ii. the actual resistor of the unknown resistor

iii. the error due to the loading effect of the voltmeter? [8+8]

2. (a) What are the international standards of mass and length?

(b) Distinguish between a primary and secondary standard.

(c) Write short notes on the concept of current standards? [5+5+6]



ii. Traceability

iii. Reliability


(b)SCALE READING PRECISION VOLTAGE CORRECTION

100 103 +390 93 +380 82.5 +2.570 72.5 +2.560 62 +250 51.7 +1.740 41.5 +1.530 31 +120 19.7 -0.310 9.5 -0.50 0 0

1 of 2


For the 10 and 50 readings in the calibration chart shown above determine theinstrument accuracy as a percentage of the reading and as a percentage of fullscale? [8+8]

4. (a) Describe the working of integrating type DVM?

(b) Explain the working of AC voltmeter using half wave rectifier?

(c) What are the advantages of using full wave rectifier over half wave rectifierwhile measuring AC voltage? [8+4+4]

5. (a) What is a Wagner’s earth connection? Explain how does it eliminate the straycapacitances.

(b) Give the list of the detectors used in both ac and dc bridges. [8+8]

6. (a) Draw the block diagram of frequency counter used for the frequency ratiomeasurement .Explain its operation.

(b) With a neat sketch explain the operation of a co-axial wave meter. [8+8]

7. (a) Derive an expression for the deflection sensitivity of electrostatic CRT.

(b) The Lissajous pattern on an CRO is stationary and has 6 horizontal and 3vertical tangencies. The frequency of the vertical input is 600Hz. Determinethe frequency of horizontal input. [9+7]

8. (a) What are the advantages of LCD display over LED display.

(b) With block diagram explain the operation of FFT spectrum analyzer.[8+2+6]

? ? ? ? ?

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? ? ? ? ?

1. (a) A voltmeter reading 70V on its 100V range and an ammeter reading 80mAon its 150mA range are used to determine the power dissipated in a resistor.Both these instruments are guaranteed to be accurate within ± 1.5% at fullscale deflection. Determine the limiting error of the power?

(b) Write short notes on accuracy and precision? [8+8]

2. (a) Distinguish between International and absolute standards

(b) A bar magnet has a cross section of 1in * 1in and a flux density of 1290 linesper square inch. Calculate the total flux in Wb

(c) Write short notes on the international standard of mass, length and volume?[4+4+8]



ii. Traceability

iii. Reliability


(b)SCALE READING PRECISION VOLTAGE CORRECTION

100 103 +390 93 +380 82.5 +2.570 72.5 +2.560 62 +250 51.7 +1.740 41.5 +1.530 31 +120 19.7 -0.310 9.5 -0.50 0 0

For the 10 and 50 readings in the calibration chart shown above determine theinstrument accuracy as a percentage of the reading and as a percentage of fullscale? [8+8]

4. (a) Write short notes on the principle of peak reading voltmeter?

1 of 2


(b) Illustrate the principle and working of ramp type DVM? Compare its perfor-mance with other types of DVM’s? [8+8]

5. (a) Explain the “parallel-connection” method of using Q-meter and Obtain theexpressions for resistance , reactance and Q factor.

(b) Give the list of the detectors used in ac bridges. [10+6]



7. (a) Distinguish between alternate and chopped modes of operation of CRO.

(b) Explain the gear wheel method for frequency measurement [8+8]

8. (a) With a schematic diagram explain the operation of pulse duration modula-tion(PDM) recording system.

(b) Draw the block diagram of a logic analyzer and explain its operation. [8+2+6]

? ? ? ? ?

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? ? ? ? ?

1. (a) Explain the following terms

i. Instrumental error

ii. Limiting error

iii. Random error

iv. Probable error

(b) The current passing through a resistor of 100 ± 0.2Ω is 2.00 ± 0.5A. Usingthe relationship P = I2R, Calculate the limiting error in the computed valueof power dissipation? [8+8]

2. (a) Describe the international standard of mass, length and volume?

(b) What are atomic standards for frequency and time? [8+8]

3. (a) What are the necessary steps taken before performing calibration?

(b) What is meant by testing, where is it performed and give the applications oftesting?

(c) Why ISO 9001 and ISO 9002 standards are required for calibration? [4+8+4]

4. (a) Write short notes on the principle of RMS voltmeter?

(b) Explain with a neat block diagram dual slope type DVM? [8+8]

5. (a) A bridge is balanced at 1 KHz and has the following constants; AB=0.5 µFcapacitance in parallel with 1 KΩ resistance; BC, 2000Ω pure resistance ;CDunknown capacitor and resistance in series; DA , C=0.5µF. Find the constantsof arm CD, and dissipation factor.

(b) What are the limitations of Wheatstone’s bridge? [10+6]

6. (a) With the help of a block diagram explain the multiplexed display techniqueused in a frequency counter.

(b) Explain in detail about frequency mode errors and period mode errors. [4+6+6]

7. Write short notes on the following controls.

(a) Delayed Sweep

(b) ALT/ CHOP mode

(c) Astigmatism [4+8+4]

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8. (a) With a schematic diagram explain the operation of pulse duration modula-tion(PDM) recording system.

(b) Draw the block diagram of a logic analyzer and explain its operation. [8+2+6]

? ? ? ? ?

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Code No: V0101/R05 Set No. 1

II B.Tech II Semester Supplementary Examinations, Apr/May 2012PROBABILITY AND STATISTICS

( Common to Civil Engineering, Mechanical Engineering, ChemicalEngineering, Mechatronics, Production Engineering, Bio-Technology and

Automobile Engineering)Time: 3 hours Max Marks: 80


? ? ? ? ?

1. (a) State and prove Baye’s theorem

(b) In a certain college 25% of boys and 10% of girls are studying mathematics.The girls constitute 60% of the students. If a student is selected at randomand is found to be studying mathematics, find the probability that the studentis a

i. girl

ii. boy [8+8]

2. (a) If X is a continuous random variable with distribution.

f(x) =

16x+ k if 0 ≤ x ≤ 3

0 elsewhere

determine

i. the value of k

ii. the mean

iii. P(1 ≤ x ≤ 2)

(b) Derive the formula to find the mean and variance of Binomial distribution[8+8]

3. (a) 2% of the items of a factory are defective. The items are packed in boxes.What is the probability that there will be

i. 2 defective items

ii. at least three defective items

(b) The marks obtained in statistics in a certain examination found to be normallydistributed. If 15% of the marks of the students ≥ 60, 40% < 30% marks,find the mean and standard deviation. [8+8]

4. A population consists of five numbers 2,3,6,8,11. Consider all possible samples ofsize two which can be drown without replacement from the population. Find

(a) The mean of the population

(b) Standard deviation of the population.

(c) The mean of the sampling distribution of means

1 of 2


(d) The standard deviation of the sampling distribution of means. [4+4+4+4]

5. (a) In a study of an automobile insurance a random sample of 80 body repaircosts had a mean of Rs. 472.35 and a standard deviation of Rs 62.35. If x isused as a point estimate to the true average repair costs, with what confidencewe can assert that the maximum error doesn’t exceed Rs.10. Find also theconfidence interval with that confidence.

(b) A manufacturer of electric bulbs claims that the percentage defectives in hisproduct doesn’t exceed 6. A sample of 40 bulbs is found to contain 5 defectives.Would you consider the claim justified? [8+8]

6. (a) To examine the hypothesis that the husbands are more intelligent than thewives, an investigator took a sample of 10 couples and administered them atest which measures the IQ as follows:

Test the hypothesis with a reasonable test at the level of significance of 0.05?

Husbands: 117 105 97 105 123 109 86 78 103 107Wives 106 98 87 104 116 95 90 69 108 85

(b) In an investigation on the machine performance the following results wereobtained:

No.of Units inspected No. of defectivesMachine 1 375 17Machine 2 450 22

Test whether there is any significant performance of two machines at α=0.05[8+8]

7. (a) Find the most possible values of x and y from the following equations

x− 5y + 4 = 0, 2x− 3y + 5 = 0

x+ 2y − 3 = 0, 4x+ 3y + 1 = 0

(b) Fit a curve of the form y = aebx for the following data [8+8]

x 1 2 3 4 5 6y 1.6 4.5 13.8 40.2 125 300

8. The following are the data on the number of twists required to break a certainkind of forged alloy bar and the percentage of two alloying elements present in themetal. Fit at least sequence regression line on x1 and x2. [16]

No. of tuirists (y) 41 49 69 65 40 50 58 57 31 36 44 57 19 31 33 43% of elements of A (x1) 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4% of elements of B (x2) 5 5 5 5 10 10 10 10 15 15 15 15 20 20 20 20

? ? ? ? ?

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? ? ? ? ?

1. (a) The probabilities that students A,B,C,D solve a problem are 1/3, 2/5, 1/5and 1/4 respectively. If all of them try to solve the problem, what is theprobability that the problem is solved.

(b) In a bolt factory machines A,B,C manufacture 20%, 30% and 50% of the totalof their output and 6%, 3% and 2% are defective. A bolt is drawn at randomand found to be defective. Find the probabilities that it is manufactured from

i. Machine A

ii. Machine B

iii. Machine C [8+8]

2. (a) If F(x) is the distribution function of X given byF (x) = 0 if x ≤ 1

= k(x−D)4 if 1 < x ≤ 3= 1 if x > 3

determine

i. f(x)

ii. k

iii. Mean

(b) Find the maximum n such that the probability of getting no head in tossinga coin n times is greater than .1 [8+8]

3. (a) Suppose 2% of the people on the average are left handed. Find

i. the probability of finding 3 or more left handed

ii. the probability of finding ≤ 1 left handed.

(b) The mean and standard deviation of a normal variate are 8 and 4 respectivelyfind

i. P(5 ≤ x ≤10)

ii. P(x ≥ 5) [8+8]

4. Sample of size 2 are taken from the population 1,2,3,4,5,6 without replacement Find

(a) The mean of the population.

(b) The standard deviation of the population.

1 of 2


(c) The mean of sampling distribution of means.

(d) The standard deviation of sampling distribution of means. [4×4]

5. (a) Experiences had shown that 20% of a manufactured product is of the topquality. In one days production of 400 articles only 50 are of top quality. Testthe hypothesis at .05 level.

(b) If the mean breaking strength of copper wire is 505 lbs with a standard de-viation of 15 lbs. The sample is 49 construct 95% confidence interval for themean.

(c) If the standard deviation of a sample is 20 and the maximum error with 99%confidence is 1.72. How large the sample might be? [5+5+6]

6. (a) To examine the hypothesis that the husbands are more intelligent than thewives, an investigator took a sample of 10 couples and administered them atest which measures the IQ as follows:

Test the hypothesis with a reasonable test at the level of significance of 0.05?

Husbands: 117 105 97 105 123 109 86 78 103 107Wives 106 98 87 104 116 95 90 69 108 85

(b) In an investigation on the machine performance the following results wereobtained:

No.of Units inspected No. of defectivesMachine 1 375 17Machine 2 450 22

Test whether there is any significant performance of two machines at α=0.05[8+8]

7. (a) Derive normal equations to fit y = axb

(b) Fit a parabola of the form y = a + bx + cx2 for the following data [6+10]

x 2 4 6 8 10y 3.07 12.85 31.47 57.38 91.29

8. Calculate the coefficient of correlation and the two lines of regression for the fol-lowing data. [16]

X 1 2 3 4 5 6 7 8 9Y 9 8 10 12 11 13 14 16 15

? ? ? ? ?

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? ? ? ? ?

1. (a) Two dice are thrown. Let A be the event that the sum of the points on faceis 9. Let B be the event that at least one number is 6. Find the probability.

i. P (A ∩B)

ii. P (A ∪B)

iii. P (A ∩Bc)

(b) Let X,Y,Z be three coins in a box. Suppose X is a fair coin. Y is two headed,and Z is weighted so that the probability of heads is 1/3. A coin is selectedat random and is tossed.

i. If head appears, find the probability that it is fair.

ii. If tail appears, find the probability that it is the coin Z. [8+8]

2. (a) Calculate expectation and variance of x, if the probability distribution of therandom variable x is given by

X -1 0 1 2 3f 0.3 0.1 0.1 0.3 0.2

(b) The probability of a man hitting a target is 1/3.

i. If he fires 5 times, what is the probability of his hitting the target at leasttwice

ii. How many times must he fire so that the probability of his hitting thetarget at least once is more than 90%. [8+8]

3. (a) Using recurrence formula find the probabilities when x=0, 1, 2, 3, 4 and 5If the mean of Poisson distribution is 3.

(b) If the masses of 300 students are normally distributed with mean 68 kgs andstandard deviation 3 kgs how many students have masses.

i. Greater then 72 kg

ii. Less than or equal to 64 kg

iii. Between 65 and 71 kg inclusive [8+8]

4. If the population is 3,6,9,15,27.

(a) List all possible samples of size 3 that can be taken without replacement fromthe finite population.

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(b) Calculate the mean of each of the sampling distribution of means.

(c) Find the standard deviation of sampling distribution of means. [5+5+6]

5. (a) A sample of 400 items is taken from a population whose standard deviationis 10. The mean of the sample is 40. Test whether the sample has come froma population with mean 38. Also calculate 95% confidence interval for theproportion.

(b) A social worker believes that greater than 25% of the couples in a certain areaare ever used any form of birth control. A random sample of 120 couples wascontacted. Twenty of them said that they have used. Test the belief if socialworker at 0.05 level. [8+8]

6. The following are the average weekly losses of worker hours due to accidents in 10industrial plants before and after a certain safety programme was put into opera-tion:

Before: 45 73 46 124 33 57 83 34 26 17After: 36 60 44 119 35 51 77 29 24 11

Test whether the safety programme is effective in reducing the number of accidentsat the level of significance of 0.05? [16]

7. Fit a parabola of the form y = a + bx + cx2 for the following data by the methodof least squares [16]

x 20 40 60 80 100 120y 5.5 9.1 14.9 22.8 33.3 46

8. Observations on price x and supply y the following data was obtained.∑x = 130,

∑y = 220,

∑x2 = 2288,

∑y2 = 5506 and

∑xy = 3467

Find

(a) coefficient of correlation

(b) The line of regression of y or x

(c) The standard error of estimate. [6+5+6]

? ? ? ? ?

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? ? ? ? ?

1. (a) There are 12 cards numbered 1 to 12 in a box. If two cards are selected whatis the probability that the sum in odd

i. With replacement

ii. Without replacement

(b) Suppose colored balls are distributed in three indistinguishable boxes as fol-lows:

Box-I Box-II Box-IIIRed 2 4 3

White 3 1 4Blue 5 3 3

A box is selected at random from which a ball is selected at a random. What isthe probability that the ball is colored

(a) red

(b) blue [6+10]

2. (a) If F(x) is the distribution function of X given byF (x) = 0 if x ≤ 1

= k(x−D)4 if 1 < x ≤ 3= 1 if x > 3

determine

i. f(x)

ii. k

iii. Mean

(b) Find the maximum n such that the probability of getting no head in tossinga coin n times is greater than .1 [8+8]

3. (a) The mean diameter is 12 mm and standard deviation 0.02 mm in a sample of200 washers produced by a machine. Find the percentage of washers producedwhose diameters lie

i. within 11.97 to 12.03 mm

ii. outside 12.03 mm

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(b) Suppose the heights of American men are normally distributed with mean=68inches and standard deviation 2.5 inches. Find the percentage of people whoseheights lie between

i. 66 inches and 71 inches

ii. atleast 6ft. [8+8]

4. A population consists of 5,10,14,18,13,24 consider all possible samples of size twowhich can be drawn without replacement from the population. Find

(a) The mean of the population.

(b) The standard deviation of the population.

(c) The mean of the sampling distribution of means

(d) The standard deviation of sampling distribution of means. [4×4]

5. (a) A sample of size 64 and mean 60 was taken from a population whose standarddeviation is 10. Find 95% confidence interval for the mean.

(b) Experience has shown that 10% of a manufactured product is of top quality.What can you say about the maximum error with 95% confidence for 100items

(c) A coin is tossed 512 times. Head turned up 244 times. Can you say that thecoin is unbiased. [5+5+6]

6. From the following data find whether there is any significant liking in the habit oftaking soft drinks among the categories of employees. [16]

EmployeesSoft drinks Clerks Teachers OfficersPepsi 10 25 65Thumsup 15 30 65Fanta 50 60 30

7. (a) Derive normal equations to fit the curve of the form y = a + bx2

(b) Fit a curve of the form y = a + bx for the following data and find ywhen x = 12 [6+10]

x 1 2 3 4 5 6 7 8 9y 9 8 10 12 11 13 14 16 15

8. Find the least squares regression equation of X1 on X2 and X3 from the followingdata. [16]

X1 3 5 6 8 12 14X2 16 10 7 4 3 2X3 90 72 54 42 30 14

? ? ? ? ?

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II B.Tech II Semester Supplementary Examinations, Apr/May 2012SOFTWARE ENGINEERING

( Common to Computer Science & Engineering, Information Technologyand Computer Science & Systems Engineering)

Time: 3 hours Max Marks: 80Answer any FIVE Questions

All Questions carry equal marks⋆ ⋆ ⋆ ⋆ ⋆

1. Discuss the key challenges facing the software Engineering. [16]

2. (a) What is non-functional requirements? Give examples for it.

(b) Explain the matrices for specifying non-functional requirements. [8+8]

3. (a) Discuss how feasibility studies is conducted.

(b) Why requirements elicitation and analysis is a difficult process? [8+8]

4. (a) Discuss the statement, “Not every software quality attribute is weighted equallyas the software design is developed”.

(b) Explain the general task set for design. [8+8]

5. Consider the interactive application of Library Management system and develop adesign model, a user model, a system image, and a system perception in the userinterface modeling. [16]

6. (a) What is CK metrics suite? State and explain the six class-based design metricsfor Object-Oriented systems.

(b) Discuss the MOOD metrics suit. [10+6]

7. (a) What is the difference between private and public uses for software metrics?

(b) Discuss the guidelines which should be applied when we collect software met-rics. [8+8]

8. (a) What is SQA plan?

(b) Some people argue that an FTR should asses programming style as well ascorrectness. Is this a good idea? Why? [8+8]

⋆ ⋆ ⋆ ⋆ ⋆

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1. (a) Explain various classes of software.

(b) Define Software. Why it does not wear out? [6+10]

2. Discuss the use of fourth generation techniques ( 4GT) for software development.[16]

3. Discuss the statement, “ Software system requirements may be derived or con-strained by social and organizational context”. [16]

4. (a) Discuss various top-down design strategies.

(b) Explain about refinement. Why always stepwise refinement is preferred?[10+6+4]

5. What are the different static and dynamic models that UML provides to documentthe design? Discuss them clearly with suitable examples. [16]

6. (a) The software analysis and design are constructive tasks, and software testingis considered to be destructive from the point of view of developer. Discuss.

(b) Who will test the software, either developer or an independent test group?Discuss the advantage and draw backs of each one.

[8+8]

7. (a) Present an argument against lines of code as a measure for software pro-ductivity. Will your case hold up when dozens or hundreds of projects areconsidered?

(b) The software used to control a photocopier requires 32,000 lines of C and 4200lines of Small talk. Estimate the number of function points for the softwareinside the copier. [8+8]

8. (a) Explain about Sample-Driven reviews.

(b) What is statistical SQA? What steps are required to perform it? [8+8]

⋆ ⋆ ⋆ ⋆ ⋆

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1. Suggest two application domains where SEI Capability model is unlikely to beappropriate. Give reasons why this is the case. [16]

2. Recommend the life cycle model (waterfall or evolutionary) for the following soft-ware systems.

(a) Enterprise Software

(b) Management Information Systems. [8+8]

3. What is a behavioural model? Discuss various types of behavioural models withexamples for each. [4+12]

4. (a) Explain about data flow and layered architectures. Differentiate betweenthem.

(b) Discuss the criteria used to assess an architectural design. [6+2+8]

5. State and explain with an example the various methods to identify object classes.[16]

6. (a) What questions do black-box tests answer?

(b) What is meant by BVA? Discuss the guidelines to create BVA test cases.

(c) Discuss about software tools for test case design. [5+5+6]

7. (a) With a sample risk information sheet, explain the RMMM plan.

(b) Discuss about software tools for risk management. [10+6]

8. (a) What is SQA plan?

(b) Some people argue that an FTR should asses programming style as well ascorrectness. Is this a good idea? Why? [8+8]

⋆ ⋆ ⋆ ⋆ ⋆

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1. Discuss about software process assessment in detail. [16]

2. Recommend the life cycle model( waterfall or evolutionary ) for the following soft-ware systems.a) Customer relations managementb) Supply chain management. [8+8]

3. Discuss the statement, “ Ethnographic studies can reveal critical process detailswhich are often missed by other requirement elicitation techniques”. [16]

4. (a) Discuss various top-down design strategies.

(b) Explain about refinement. Why always stepwise refinement is preferred?[10+6+4]

5. What is meant by OOD? Explain various stages in OOD? [16]

6. (a) What is meant by software quality? Discuss clearly the McCall‘s softwarequality factors.

(b) Discuss about ISO 9126 Quality factors. [10+6]

7. (a) Compute the function point value for a project with the following informationdomain characteristics.Number of external inputs: 32Number of external outputs: 60Number of external inquires: 24Number of external interface files: 2Number of internal logical files: 8Assume that all complexity adjustment values are average.

(b) What is an indirect measure? And how are such measures common in softwaremetrics work? [8+8]

8. (a) Discuss the role of an SQA group.

(b) Distinguish among bug, error, and defect. [10+6]

⋆ ⋆ ⋆ ⋆ ⋆

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Eca [r10] April 2012

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