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MCQ ON ALTERNATOR PAGE - 1

1.

A 4-pole, 50 Hz alternator will have a rotational speed of

Answer/ Hint      

Answer : B

Explanation :

2.

An exciter used for field excitation of an alternator will be a

Answer/ Hint      

Answer : B

Explanation :

3.

The reason of using laminated cores in the stator of an alternator is to

Answer/ Hint      

Answer : B

Explanation :

4.

D.C and A.C generators are similar in one important respect that is:

Answer/ Hint      

Answer : C

Explanation :

5.

An 8- pole alternator rotates at 750 rpm it per cycle periodic time will be:

Answer/ Hint      

Answer : B

Explanation :

6.

Alternators designed to be driven by steam turbines are built for:

Answer/ Hint      

Answer : A

Explanation :

7.

Single-phase portable generators are generally made in the range of :

Answer/ Hint      

Answer : D

Explanation :

8.

An alternator supplied electric power to various kinds of loads of a factory. If the phase sequence of the alternator is changed, it will affect the

Answer/ Hint      

Answer : B

Explanation :

9.

The values of pitch factor and distribution factor for an alternator are 0.9 and 0.8 respectively. This will develop an e.m.f lesser than an alternator having full pitch coil and concentrated windi

Answer/ Hint      

Answer : B

Explanation :

10.

The winding of a 4-pole alternator is having 36 slots and a coil span of 1 to 8. It is short pitched by …. Electrical degrees.

Answer/ Hint      

Answer : B

Explanation :

11.

The number of slip rings used in a 3 phase, star connected alternator having a rotating armature will be:

Answer/ Hint      

Answer : C

Explanation :

12.

The pitch factor is defined as the ratio of the e.m.f of the

Answer/ Hint      

Answer : B

Explanation :

13.

The rotor of a salient pole alternator has 12 poles. The number of cycle of e.m.f in one revolution will be

Answer/ Hint      

Answer : C

Explanation :

14.

In large-sized alternator, dampers are used to

Answer/ Hint      

Answer : C

Explanation :

15.

The number of electrical degrees which passes through in one revolution of a 6-pole alternator is

Answer/ Hint      

Answer : B

Explanation :

16.

The waveform of the e.m.f generated by an alternator should be :

Answer/ Hint      

Answer : C

Explanation :

17.

The field circuit of a hydro alternator is supplied with

Answer/ Hint      

Answer : D

Explanation :

18.

when a coil/conductor moves at right angle to the magnetic flux, the induced e.m.f will be

Answer/ Hint      

Answer : C

Explanation :

19.

salient pole type rotors as compared to the cylindrical pole type rotors are

Answer/ Hint      

Answer : B

Explanation :

20.

The frequency generated by a 8-pole alternator rotating at 600 r.p.m. will be

Answer/ Hint      

Answer : B

Explanation :

21.

The frequency of voltage generated by an altenator having 4 poles and rotating at 1800 R.P.M is

Answer/ Hint      

Answer : A

Explanation :

22.

A 50 Hz alternator will run at the greatest possible speed if it is wound for …. poles

Answer/ Hint      

Answer : D

Explanation :

23.

When Speed of an alternator is changed from 3600 R.P.M to 1800 R.P.M, the generated e.m.f per phase will become

Answer/ Hint      

Answer : A

Explanation :

24.

The power factor of an alternator is determined by its

Answer/ Hint      

Answer : B

Explanation :

25.

For proper parallel operation, polyphase alternators must have the same

Answer/ Hint      

Answer : B

Explanation :

26.

The number of poles in turbo alternator is

Answer/ Hint      

Answer : A

Explanation :

27.

The frequency of e.m.f generated by an alternator depends upon the speed N and No. of poles is given by

Answer/ Hint      

Answer : C

Explanation :

28.

The current from the stator of an alternator is taken out to the external load circuit through

Answer/ Hint      

Answer : C

Explanation :

29.

In a synchronous machine, the stator frame is made of

Answer/ Hint      

Answer : C

Explanation :

30.

The stator of an alternator gets overheated due to

Answer/ Hint      

Answer : D

Explanation :

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