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SASI INSTITUTE OF TECHNOLOGY AND ENGINEERING DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING TECHNICAL QUIZ

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OBJECTIVES ON CORE SUBJECTS OF ELECTRICAL

### Transcript of TECHNICAL QUIZ ROUND-1

SASI INSTITUTE OF TECHNOLOGY AND ENGINEERING

DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING

TECHNICAL QUIZ

1.Out of the following which is not a poor conductor ?(a) Cast iron (b) Copper(c) Carbon (d) Tungsten

2. In a series circuit with unequal resistances(a) the highest resistance has the most of the current through it(b) the  lowest resistance has the highest voltage drop(c) the  lowest resistance has the highest current(d) the highest resistance has the highest voltage drop

3.The main consideration for higher and higher operating voltage of transmission is to (a) increase the efficiency of transmission (b) reduce power losses (c) increase power transmission capability (d) both (a) and (b)

4. Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open(a) there will be heavy current in the main line(b) rest of the two bulbs will not light(c) all three bulbs will light(d) the other two bulbs will light

5. An RLC series. circuit remains predominantly inductive (a) at resonance frequency (b) below resonance frequency (c) above resonance frequency (d) at the lower half power frequency

6. In a D.C. machine stray loss is the sum of(a) total copper loss and mechanical loss(b) armature copper loss and iron loss(c) shunt field copper loss and mechanical loss(d) iron loss and mechanical loss

7. The form factor is the ratio of(a)    peak value to r.m.s. value(6)    r.m.s. value to average value(c) average value to r.m.s. value(d) none of the above

8. In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will(a) increase (b) decrease(c) remain the same(d) initially increase and then decrease

9. The main criterion for selection of the size of a distribution for a radial distribution system is(a) voltage drop     (b) corona loss (c) temperature rise (d) capital cost

10. A zener diode is used for a. Voltage regulation b. Rectification c. Noise suppression d. Blocking a.c.

11. The insulating material used between the commutator segments is normally(a) graphite (b) paper(c) mica(d) insulating varnish

12. The Laplace transform of an impulse function is

a. 1 b.1/s c.1/s^2 d.0

13.Which of the following motor has relatively wider range of speed control.(a)     Synchronous motor(6)     Ship ring induction motor(c)    Squirrel cage induction motor(d)    D.C. shunt motor

14. The bridge used for measurement of inductance is

a. Wheatstone Bridge b. Kelvin Double Bridge c. Anderson Bridge d. Schering Bridge

15. If an induction machine is run at above synchronous speed, it acts as (a) a synchronous motor (b) an induction generator (c) an inductor motor (d) none of the above

16. The phenomenon of rise in voltage at the receiving end of the open-circuited or lightly loaded line is called the(a) See back effect   (b) Ferranti effect (c) Raman effect (d) Proximity effect

17. Which of the following is a universal gate?

a. AND b. OR c. NOR d. XOR

18. The insulation of modern EHV lines is designed based on (a) the lightning voltage (b) corona (c) radio interface (d) switching voltage

19. A booster is a(a)    series wound generator(b)    shunt wound generator(c)    synchronous generator (d)     none of the above

20. In D.C. generators, the brushes on commutator remain in contact with conductors which(a)     lie under south pole(b)     lie under north pole(c) lie under interpolar region(d) are farthest from the poles

21. A.C. servomotor resembles    (a)    two phase induction motor(b)    Three phase induction motor(c)    direct current series motor(d)    universal motor

22. With feed back _____ reduces.(a)     system stability(b)     system gain(c)     system stability and gain(d)     none of the above

23. Distribution lines in India generally use(a) wooden poles     (b) R.C.C. poles(c) steel towers        (d) Lattice Structure Poles

24. For a purely inductive circuit which of the following is true ?(a) Apparent power is zero(b) Reactive power is zero(c) Actual power of the circuit is zero(d) Any capacitance even if present in the circuit will not be charged

25. A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is(a)    slop speed operation (b)    high starting torque (c)    low windage losses (d)    all of the above

26. The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that(a) both waves must have same frequency(b) both   waves  must  have identical peak values(c) both waves must have zero value at the same time(d) none of the above

27. Which of the following is the best method for determining the stability and transient response ?(a) Root locus    (b) Bode plot(c) Nyquist plot(d) M & N Circle

28. In majority of instruments damping is provided by(a)    fluid friction     (b)    spring(c)    eddy currents    (d)    all of the above

29. The inductance of a coil will increase under all the following conditions except(a) when more length for the same number of turns is provided(6) when the number of turns of the coil increase(c) when more area for each turn is provided(d) when permeability of the core increases

30. The presence of ozone due to corona is harmful because it(a)     reduces power factor (b)     corrodes the material(c)    gives odour(d)    transfer energy to the ground

1.The Rotor used in alternators of hydro-electric stations is……

2. A fuse wire should be of material that has __________ resistivity and __________ melting points.

3. The most common type of ac motor is the…..

1.Average ash content in India coal is about…….%

2.Signal flow graphs can be used to represent……system

3. The bridge used for measurement of inductance is……

1.Nuclear Reactor is made up of……

2. Zener diodes semiconductors are……Doped elements.

3.Root locus technique was introduced by…..

1. Most of the generators in thermal power plants run at….

2.Intersection point of Asymptotes are ….

3.In an oil filled transformer , oil is Provided for…..

1. The fact that a conductor carries more current on the surface as compared to core, is known as……

2.In general……..is the element that stores Potential energy.

3.A Permanent Magnet Moving coil instrument can be measured

1. Kirchhoff's second law is based on law of conservation of….

2.Transformer action Requires……….

3.The Economic size of the conductor is determined by…………..

1. Ampere second could be the unit of…..

2.Protection against water hammer action in Hydro plant is Provided by …….

3.Hamming noise in Transformers is due to …..

1. Electrons in the outer orbit are called…..

2.The type of dc generator used for arc welding……..

3.The Efficiency of a thermal power plant is about…………

1. A two-terminal variable resistor is known as a……

2.Most commonly used moderator materials….

3.For P-pole machine relation between electrical and mechanical is……

1. In a three-phase system, the voltages are separated by….

A…….loop is loop consisting of single branch.

3.Reciprocity condition of transmission line parameters……