Electrical Engineering Mcqs Practice Test

Question 1

A conductor 2 meters long moves at right angles to a magnetic field of flux density 1 tesla with a velocity of 12.5 m/s. The induced e.m.f. in the conductor will be____________?

Accepted Answer

C. 25V

Question 2

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

Accepted Answer

C. 12 H

Question 3

Lenz’s law is a consequence of the law of conservation of__________?

Accepted Answer

C. energy

Question 4

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

Accepted Answer

B. 1.0

Question 5

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___________?

Accepted Answer

D. 48 mH

Question 6

The self inductances of two coils are 8 mH and 18 mH. If the co-efficients of coupling is 0.5, the mutual inductance of the coils is______________?

Accepted Answer

C. 6 mH

Question 7

In case of an inductance, current is proportional to___________?

Accepted Answer

B. magnetic field

Question 8

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

Accepted Answer

C. Actual power of the circuit is zero

Question 9

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

Accepted Answer

D. 4 A/s

Question 10

Two coils have inductances of 8 mH and 18 mH and a co-efficient of coupling of 0.5. If the two coils are connected in series aiding, the total inductance will be______________?

Accepted Answer

B. 38 mH

Question 11

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

Accepted Answer

A. 3 mH

Question 12

Which of the following is unit of inductance ?

Accepted Answer

B. Henry

Question 13

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

Accepted Answer

B. Inductance

Question 14

A laminated iron core has reduced eddy-current losses because____________?

Accepted Answer

B. the laminations are insulated from each other

Question 15

The magnitude of the induced e.m.f. in a conductor depends on the______________?

Accepted Answer

D. rate of change of flux-linkages

Question 16

Which of the following is not a unit of inductance ?

Accepted Answer

B. Coulomb/volt ampere

Question 17

Mutually inductance between two magnetically-coupled coils depends on____________?

Accepted Answer

D. all of the above

Question 18

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

Accepted Answer

B. Lenz

Question 19

If current in a conductor increases then according to Lenz’s law self-induced voltage will____________?

Accepted Answer

C. produce current opposite to the in-creasing current

Question 20

Air-core coils are practically free from______________?

Accepted Answer

C. both (A) and (B)