electrical

Transformer MCQ Objective Questions and Answers Page - 1

1.

The basic function of a transformer is to change

Answer/ Hint       Comment On Question

Answer : A

Explanation :

2.

In an ordinary transformer which of the following does not change

Answer/ Hint       Comment On Question

Answer : C

Explanation :

In an ordinary transformer one parameter cannot be changed that is frequency.

3.

The efficiency of a power transformer is around

Answer/ Hint      

Answer : D

Explanation :

4.

In a transformer, electrical power is transferred from primary to secondary

Answer/ Hint       Comment On Question

Answer : B

Explanation :

5.

The two windings of a transformer are

Answer/ Hint      

Answer : B

Explanation :

6.

Transformer action requires a

Answer/ Hint      

Answer : C

Explanation :

7.

The  flux created by the current flowing through the primary winding induces emf in

Answer/ Hint      

Answer : D

Explanation :

8.

The primary and secondary  windings of a power transformer always have

Answer/ Hint      

Answer : A

Explanation :

9.

The iron core in a transformer provides a _____path to the main flux

Answer/ Hint      

Answer : A

Explanation :

10.

If rated dc voltage is applied instead of ac to the primary of a transformer

Answer/ Hint      

Answer : B

Explanation :

11.

A transformer transforms

Answer/ Hint      

Answer : C

Explanation :

12.

For an ideal transformer the windings should have

Answer/ Hint       Comment On Question

Answer : D

Explanation :

For an ideal transformer the windings should have no ohmic resistance on either side.

13.

The core flux in transformer depends mainly on

Answer/ Hint       Comment On Question

Answer : B

Explanation :

The core flux in transformer depends mainly on Supply voltage and frequency

14.

When voltage is transformed  from primary to secondary then it is ______

Answer/ Hint      

Answer : B

Explanation :

15.

A transformer steps up the voltage by a factor 100. The ratio of current in the primary to that in the secondary is

Answer/ Hint      

Answer : B

Explanation :

16.

If the applied voltage to a transformer primary is increased by keeping the V/f ratio fixed, then the magnetizing current and the core loss will, respectively :

Answer/ Hint      

Answer : D

Explanation :

17.

If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced to 50% (assuming that the magnetic circuit remain unsaturated), the maximum core flux density will&l

Answer/ Hint      

Answer : A

Explanation :

18.

The applied voltage of a certain transformer is increased by 75%; while the frequency of the applied voltage is reduced by 25%. The maximum core flux density will

Answer/ Hint      

Answer : B

Explanation :

19.

If the supply frequency of a transformer is increased, keeping the supply voltage constant , then

Answer/ Hint      

Answer : A

Explanation :

20.

The low voltage winding of a 400/230v single phase 50 Hz transformer is to be connected to a 25 Hz supply. In order to keep the magnetization current at the same level in both the cases the voltage

Answer/ Hint      

Answer : C

Explanation :

21.

A single phase transformer rated for 220/240V,  50Hz operates at no load at 220 V , 40 Hz. This frequency operation at rated voltage  results in which one of the following

Answer/ Hint      

Answer : D

Explanation :

22.

A transformer core is laminated to

Answer/ Hint      

Answer : B

Explanation :

23.

The degree of mechanical vibrations produced by the laminations of a transformer depends on

Answer/ Hint      

Answer : D

Explanation :

24.

The no-load current drawn by transformer is usually what percent of the full-load current?

Answer/ Hint      

Answer : B

Explanation :

25.

The path of magnetic flux in a transformer should have

Answer/ Hint      

Answer : D

Explanation :

26.

No-load in a transformer is carried out to determine

Answer/ Hint      

Answer : C

Explanation :

27.

The dielectric strength of transformer oil is expected to be

Answer/ Hint      

Answer : B

Explanation :

28.

Sumper’s test is conducted on transformer to determine

Answer/ Hint      

Answer : A

Explanation :

29.

The permissible flux density in case of cold rolled grain-oriented steel is around

Answer/ Hint      

Answer : A

Explanation :

30.

The efficiency of a transformer will be maximum when

Answer/ Hint      

Answer : D

Explanation :

31.

No-load current in a transformer

Answer/ Hint      

Answer : A

Explanation :

32.

The purpose of providing an iron core in a transformer is to

Answer/ Hint      

Answer : C

Explanation :

33.

Which of the following is not a part of transformer installation?

Answer/ Hint      

Answer : D

Explanation :

34.

While conducting short circuit test on a transformer the following side is short-circuited

Answer/ Hint      

Answer : B

Explanation :

35.

In the transformer following winding has got more cross-sectional area

Answer/ Hint      

Answer : A

Explanation :

36.

A transformer transforms

Answer/ Hint      

Answer : C

Explanation :

37.

A transformer cannot raise or lower the voltage of a D.C supply because

Answer/ Hint      

Answer : C

Explanation :

38.

Primary winding of a transformer

Answer/ Hint      

Answer : C

Explanation :

39.

Which winding in a transformer has more number of turns

Answer/ Hint      

Answer : B

Explanation :

40.

Efficiency of a power transformer is of the order of

Answer/ Hint      

Answer : B

Explanation :

Transformer MCQ Objective Questions and Answers Page - 1
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