EASY

12th CBSE

IMPORTANT

Earn 100

A wire $40 cm$ long bent into a rectangular loop $15 cm \times 5 cm$ is placed perpendicular to the magnetic field whose flux density is $0 .8 Wb m^{- 2}$ . Within $1.0$ second, the loop is changed into a $10 cm$ square and flux density increases to $1 .4 Wb m^{- 2}$ . Calculate the value of induced emf.

Important Questions on Electromagnetic Induction

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 8

An air-cored solenoid of length

50 cm

and area of cross-section

28 {cm}^{2}

has

200

turns and carries a current of

5.0 A

. On switching off, the current decreases to zero within a time interval of

1.0 ms

. Find the average emf induced across the ends of the open switch in the circuit.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 9

A closed coil consists of

500

turns on a rectangular frame of area

4.0 {cm}^{2}

and has a resistance of

50 Ω

. It is kept with its plane perpendicular to a uniform magnetic field of

0 .2 Wb m^{- 2}

. Calculate the amount of charge flowing through the coil when it is turned over (rotated through

180 °

). Will this answer depend on the speed with which the coil is rotated?

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 10

A conducting circular loop is placed in a uniform transverse magnetic field of

0.02 T

. Somehow, the radius of the loop begins to decrease at a constant rate of

1.0 mm / s

. Find the emf induced in the loop at the instant when the radius is

2 cm

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 1

A straight conductor

1

metre long moves at right angles to both, its length and a uniform magnetic field. If the speed of the conductor is

2 .0 {ms}^{- 1}

and the strength of the magnetic field is

10^{4}

gauss, find the value of induced emf in volt.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 2

If a

10 m

long metallic bar moves in a direction at right angle to a magnetic field with a speed of

5 .0 {ms}^{- 1}

25 V

emf is induced in it. Find the value of the magnetic field intensity.

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 3

A horizontal telephone wire

1 km

long is lying east-west in earth’s magnetic field. It falls freely to the ground from a height of

10 m

. Calculate the emf induced in the wire on striking the ground. Given

B_{H} = 0 .32 G

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 4

A horizontal wire

24 cm

long falls in the field of flux density

0.8 T

. Calculate the emf induced in it at the end of

3 s

, after it was dropped from rest. Suppose the wire moves perpendicular to its length as well as to magnetic field. Take

g = 9 .8 m s^{- 2}

EASY

12th CBSE

IMPORTANT

New Simplified Physics (Vol 1) For Class 12>Chapter 6 - Electromagnetic Induction>Problems For Practice>Q 5

The two rails of a railway track, insulated from each other and the ground are connected to a millivoltmeter. What is the reading of the voltmeter when a train travels at a speed of

180 km h^{- 1}

along the track, given that the vertical component of the earth’s magnetic field is

0 .2 \times 10^{- 4} Wb m^{- 2}

and the rails are separated by

1 m

A wire 40 cm long bent into a rectangular loop 15 cm×5 cm is placed perpendicular to the magnetic field whose flux density is 0.8 Wb m−2. Within 1.0 second, the loop is changed into a 10 cm square and flux density increases to 1.4 Wb m−2. Calculate the value of induced emf.

Important Questions on Electromagnetic Induction

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