Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 36

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A coil having $100$ turns and area of $0.001 m^{2}$ is free to rotate about an axis. The coil is placed perpendicular to a magnetic field of $1.0 Wb m^{- 2}$ . If the coil is rotated rapidly through an angle of $180 °$ , how much charge will flow through the coil? The resistance of the coil is $10 Ω$ .

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Important Questions on Electromagnetic Induction

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 37

A coil of effective area

4 m^{2}

is placed at right angles to the magnetic field

B

. The emf of

0.32 V

is induced in the coil, when the field is reduced to

20 %

of its initial value in

0.5 s

. Find

B

.

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 38

A coil having number of turns

N

and cross-sectional area

A

is rotated in a uniform magnetic field

B

with an angular velocity

ω

. The maximum value of the emf induced in it is-

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 39

A copper disc of radius

0.1 m

is rotated about its centre with

10

revolutions per second in a uniform magnetic field of

0.1 tesla

with its plane perpendicular to the field. The emf induced across the radius of disc is

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 40

The magnetic flux through a coil varies with time as

ϕ = 5 t^{2} + 6 t + 9

. The ratio of emf at

t = 3 s

to

t = 0 s

will be

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 41

The magnetic flux through each turn of a

100

turn coil is

(t^{3} - 2 t) \times 10^{- 3} Wb

, where

t

is in second. The induced emf at

t = 2 s

is

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 42

A conducting rod is rotated in a plane perpendicular to a uniform magnetic field with constant angular velocity. The correct graph between the induced emf

(e)

across the rod and time

(t)

is

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 43

A small magnet is along the axis of a coil and its distance from the coil is

80 cm

. In this position the flux linked with the coil is

4 \times 10^{- 5} Weber

turns . If the coil is displaced

40 cm

towards the magnet in

0.08

s

, then the induced emf produced in the coil will be

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Physics Crash Course MHT-CET>Chapter 18 - Electromagnetic Induction>Exercise 1>Q 44

The magnetic flux in a closed circuit of resistance

10 Ω

varies with time as

ϕ = (2 t - 4 t^{2} + 1)

. The current in the loop will change its direction after a time of