Electromagnetic induction is-not used in ___________________.

(a)

transformer

(b)

room heater

(c)

AC generator

(d)

choke coil

Lenz's law is in accordance with the law of ________________.

(a)

conservation of charges

(b)

conservation of flux

(c)

conservation of momentum

(d)

conservation of energy

The unit henry can also be written as ______________.

(a)

VS A^-1

(b)

Wb A^-1

(c)

Ωs

(d)

all

The self-inductance of a straight conductor is ________________.

(a)

zero

(b)

infinity

(c)

very large

(d)

very small

An emf of 12V is induced when the current in the coil changes at the rate of 40 A S^-1. The coefficient of self induction of the coil is __________________.

(a)

0.3 H

(b)

0.003 H

(c)

30 H

(d)

4.8 H

An emf of 12V is induced when the current in the coil changes at the rate of 40 A S^-1. The coefficient of self-induction of the coil is _______________.

(a)

0.3 H

(b)

0.003 H

(c)

30 H

(d)

4.8 H

Transformer works on _____________.

(a)

AC only

(b)

DC only

(c)

both AC and DC

(d)

AC more effectively than DC

Which of the following cannot be stepped up in a transformer?

(a)

input current

(b)

input voltage

(c)

input power

(d)

all

The magnitude of the induced emf in a conductor depends on the _______________.

(a)

flux density of the magnetic field

(b)

amount of flux cut

(c)

amount of flux linkages

(d)

rate of change of flux

If a secondary coil has 40 turns, and a primary coil with 20 turns is charged with 50V of potential difference, then potential difference in secondary would be ________________.

(a)

50 V

(b)

25 V

(c)

60 V

(d)

100 V

In the following figure the key is dosed. Which statement is correct?

(a)

momentary current flows in Y circuit from B to A

(b)

momentary current flows in Y circuit from A to B

(c)

no current flows along AB

(d)

the coil Y is attracted to X

Which current- time graph represents the steady movement of short magnet through a coil XY?

(a)

(b)

(c)

(d)

In Fleming's right hand rule, the forefinger represents the direction of ____________.

(a)

motion of the conductor

(b)

magnetic field

(c)

induced current

(d)

induced emf

The unit of self inductance is ________________.

(a)

Henry

(b)

Ampere

(c)

Farad

(d)

Ohm

The self inductance of a coil is ________________.

(a)

directly proportional to N

(b)

inversely proportional to N

(c)

directly proportional to N²

(d)

inversely proportional to N²