electrical

Electromagnetic Induction MCQ Questions and Answers

1.

The property of coil by which a counter e.m.f is induced in it. when the current through the coil changes is known as

Answer/ Hint      

Answer : A

Explanation :

2.

As per faraday’s law of electromagnetic induction, an e.m.f is induced in a conductor whenever it

Answer/ Hint      

Answer : C

Explanation :

3.

Which of the following circuit elements stores energy in the electromagnetic filed?

Answer/ Hint      

Answer : A

Explanation :

4.

The inductance of a coil will increase under all the following conditions excepts

Answer/ Hint      

Answer : A

Explanation :

5.

Higher the self-inductance of the coil

Answer/ Hint      

Answer : D

Explanation :

6.

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

Answer/ Hint      

Answer : B

Explanation :

7.

An open coil has

Answer/ Hint      

Answer : B

Explanation :

8.

Both the number of turn and core length of an inductive coil are doubled. Its self-inductance will be

Answer/ Hint      

Answer : B

Explanation :

9.

If current in a conductor increases then according to lenz’s law self-inductance voltage will

Answer/ Hint      

Answer : C

Explanation :

10.

The direction of induced e.m.f can be found by

Answer/ Hint      

Answer : B

Explanation :

11.

Air-core coils are practically free from

Answer/ Hint      

Answer : C

Explanation :

12.

The magnitude of the induced e.m.f in a conductor depends upon

Answer/ Hint      

Answer : D

Explanation :

13.

Mutually inductance between two magnetically-coupled coils depends upon

Answer/ Hint      

Answer : D

Explanation :

14.

A laminated iron core has reduced eddy-current losses because

Answer/ Hint      

Answer : B

Explanation :

15.

The law that the induced e.m.f and current always oppose the cause producing them is due to

Answer/ Hint      

Answer : B

Explanation :

16.

Which of the following is not a unit of inductance?

Answer/ Hint      

Answer : B

Explanation :

17.

In case of an inductance, current is proportional to

Answer/ Hint      

Answer : B

Explanation :

18.

Which of the following circuit elements will oppose the change in circuit current?

Answer/ Hint      

Answer : B

Explanation :

19.

For a purely inductive circuit which of the following is true?

Answer/ Hint      

Answer : C

Explanation :

20.

Which of the following is unit of inductance?

Answer/ Hint      

Answer : B

Explanation :

21.

An e.m.f of 16 volts is induced in a coil of inductance 4H. the rate of change of current must be

Answer/ Hint      

Answer : D

Explanation :

22.

The core of the coil has a length of 200 mm. the inductance coil of 6 mH. If the core length is doubled, all other quantities, remaining the same, the inductance will be

Answer/ Hint      

Answer : A

Explanation :

23.

The self-inductance of two coils are 8 mH. If the co-efficient of coupling is 0.5, the mutual inductance of the coil is

Answer/ Hint      

Answer : C

Explanation :

24.

Two coil have inductance of 8 mH and 18mH and co-efficient of coupling of 0.5. if the two coils are connected in series aiding, the total inductance will be

Answer/ Hint      

Answer : B

Explanation :

25.

A 200 turn coil has an inductance of 12 mH. If the number of turns is increased to 400 turns, all other quantities ( area, length etc.) remaining the same, the inductance will be

Answer/ Hint      

Answer : D

Explanation :

26.

Two coils have self-inductance of 10 h and 2 h, the mutual inductance being zero. If the two coils are connected in series, the total inductance will be

Answer/ Hint      

Answer : C

Explanation :

27.

In case all the flux from the current in coil 1 links with coil 2, the co-efficient of coupling will be

Answer/ Hint      

Answer : B

Explanation :

28.

The energy in joules stored in magnetic field of 0.15 h inductance with a 180 mA current will be

Answer/ Hint      

Answer : B

Explanation :

29.

A coil with negligible resistance has 50 V across it with 10 mA. The inductive reactance is

Answer/ Hint      

Answer : D

Explanation :

30.

Lenz’s law is a consequence of the law of conversion of

Answer/ Hint      

Answer : C

Explanation :

31.

The co-efficient of coupling between the air core coils depends upon

Answer/ Hint      

Answer : C

Explanation :

32.

An average voltage of 10 v is induced in a250 turns solenoid as a result of a change in flux which occurs in 0.5 seconds. The total flux change is

Answer/ Hint      

Answer : D

Explanation :

33.

A 500 turns solenoid develops an average induced voltage of 60 V. over what time interval must a flux change of 0.06 Wb occur to produce such a voltage?

Answer/ Hint      

Answer : C

Explanation :

34.

Which of the following inductor will have the least eddy current losses?

Answer/ Hint      

Answer : A

Explanation :

35.

A coil induces 350 mV when the current changes at the rate of 1 A/s. the value of inductance is

Answer/ Hint      

Answer : B

Explanation :

36.

Two 300 µH coils in series without mutual coupling have a total inductance of

Answer/ Hint      

Answer : B

Explanation :

37.

Current charging from 8 A to 12 a in on second induced 20 volts in a coil. The value of inductance is

Answer/ Hint      

Answer : C

Explanation :

38.

Which circuit element will oppose the change in circuit current?

Answer/ Hint      

Answer : B

Explanation :

39.

A crack in the magnetic path of an inductor will result in

Answer/ Hint      

Answer : D

Explanation :

40.

A coil is wound on iron core which carries current I. the self-induced voltage in the coil is not affected by

Answer/ Hint      

Answer : B

Explanation :

41.

Which of the following statements is correct?

Answer/ Hint      

Answer : C

Explanation :

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Electromagnetic Induction MCQ Questions and Answers