set 8 MCQ Questions & Answers Detailed Explanation

Question : 1

At the time of short circuit, the current in the circuit

a) does not change

b) increases heavily

c) reduces substantially

d) vary continuously

Question : 2

Transformers are used

a) in AC circuits only

b) in both DC and AC circuits

c) in DC circuits only

d) neither in DC nor in AC circuits

Question : 3

To convert mechanical energy into electrical energy, one can use

a) AC dynamo

b) DC dynamo

c) motor

d) Both (a) & (b)

Question : 4

According to international convention of colour coding in a wire

a) live is red, neutral is green and earth is black

b) live is brown, neutral is blue and earth is black

c) live is red, neutral is black and earth is green

d) live is red, neutral is black and earth is green

Question : 5

Faraday’s laws are consequence of conservation of

a) energy and magnetic field

b) charge

c) energy

d) magnetic field

Question : 6

Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R).
Assertion (A):
Transformer is useful for stepping up or stepping down voltages.
Reason (R):
Transformer is a device used in D.C. circuits.
In the context of the above two statements, which one of the following is correct?

a) (A) is true, but (R) is false

b) Both (A) and (R) are true and (R) is the correct explanation of (A)

c) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

d) (A) is false, but (R) is true