ELECTROMAGNETIC INDUCTION QUIZ

The self inductances of two coils are 8 mH and 18 mH. If the coefficient of coupling is 0.5, the mutual inductance of the coils is

18 mH

6 mH

12 mH

36 mH

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Condenser

Inductance

Resistance

Variable resistor

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YOUR ANSWER : ?

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

12 V

15 V

10 V

25 V

TRUE ANSWER : ?
YOUR ANSWER : ?

Increasing the field or increasing the current will decrease the force on the conductor.

No

Yes

TRUE ANSWER : ?
YOUR ANSWER : ?

Air-core coils are practically free from

Hysteresis losses

None of the listed here

Eddy current losses

Both Hysteresis losses & Eddy current losses

TRUE ANSWER : ?
YOUR ANSWER : ?

Which of the following is unit of inductance?

Hennry

Ampere turns

Ohm

Weber/metre

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YOUR ANSWER : ?

If current in a conductor increases then according to Lenz's law self-induced voltage will

Aid the applied voltage

Produce current opposite to the increasing current

Aid the increasing current

Tend to decrease the amount of current

TRUE ANSWER : ?
YOUR ANSWER : ?

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

2.5

1.0

2.0

0.5

TRUE ANSWER : ?
YOUR ANSWER : ?

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

12 mH

24 mH

48 mH

3 mH

TRUE ANSWER : ?
YOUR ANSWER : ?

An open coil has

Zero resistance and high inductance

Infinite resistance and zero inductance

Infinite resistance and normal inductance

Zero resistance and inductance

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YOUR ANSWER : ?

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