Electrical Engineering Mcqs Practice Test

Question 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__________?

Accepted Answer

A. self-inductance

Question 2

The direction of induced e.m.f. can be found by_____________?

Accepted Answer

B. Lenz’s law

Question 3

An open coil has_____________?

Accepted Answer

B. infinite resistance and zero inductance

Question 4

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

Accepted Answer

A. when more length for the same number of turns is provided

Question 5

As per Faraday’s laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it_______________?

Accepted Answer

C. cuts magnetic flux

Question 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_____________?

Accepted Answer

B. decrease

Question 7

Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be_____________?

Accepted Answer

B. doubled

Question 8

Higher the self-inductance of a coil_____________?

Accepted Answer

D. longer the delay in establishing steady current through it

Question 9

Which of the following circuit element stores energy in the electromagnetic field  ?

Accepted Answer

A. Inductance

Question 10

Those magnetic materials are best suited for making armature and transformer cores which have ________ permeability and ________ hystersis loss

Accepted Answer

C. high, low

Question 11

A material for good magnetic memory should have____________?

Accepted Answer

D. high retentivity

Question 12

If the area of hysteresis loop of a material is large, the hysteresis loss in this material will be____________?

Accepted Answer

C. large

Question 13

The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is__________Vs

Accepted Answer

B. 20

Question 14

The rate of rise of current through an inductive coil is maximum_____________?

Accepted Answer

B. at the start of the current flow

Question 15

Permanent magnets are normally made of_____________?

Accepted Answer

A. alnico alloys

Question 16

The unit of magnetic flux is______________?

Accepted Answer

B. weber

Question 17

Point out the wrong statement. Magnetic leakage is undesirable in electric machines because it___________?

Accepted Answer

A. lowers their power efficiency

Question 18

An air gap is usually inserted in magnetic circuits to____________?

Accepted Answer

C. prevent saturation

Question 19

In a magnetic material hysteresis loss takes place primarily due to___________?

Accepted Answer

D. it high retentivity

Question 20

Hysteresis loss least depends on____________?

Accepted Answer

D. ambient temperature