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A random shaped conducting wire is moved in a uniform magnetic field as shown. Find motional emf induced across its ends at this instant for which its coordinates are mentioned. [ $v$ is along x-axis.]

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Important Questions on Electromagnetic Induction

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

The figure shows a bar magnet and a metallic coil. Consider four situations. (I) Moving the magnet away from the coil. (II) Moving the coil towards the magnet. (III) Rotating the coil about the vertical diameter. (IV) Rotating the coil about its axis.

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An emf in the coil will be generated for the following situations.

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

Directions: Each of the following sentences in this section has a blank space and four words or group of words given after the sentence. Select the word or group of words you consider most appropriate for the blank space and indicate your response on the Answer Sheet accordingly.

Every rash driver becomes a ____ killer.

EASY

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

In a coil of resistance $100 Ω$ , a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is:
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MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

800

turn coil of the effective area

0.05 m^{2}

is kept perpendicular to the magnetic field

5 \times 10^{- 5} T .

When the plane of the coil is rotated by

90^{o}

around any of its coplanar axis in

0.1 s,

the emf induced in the coil will be:

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A conducting circular loop made of a thin wire has area

3.5 \times 10^{- 2} m^{2}

and resistance

10 Ω

It is placed perpendicular to a time-dependent magnetic field

B (t) = (0.4 T) \sin (50 π t)

. The field is uniform in space. Then the net charge flowing through the loop during

t = 0 s

and

t = 10 ms

is close to:

HARD

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A conducting metal circular-wire-loop of radius

r

is placed perpendicular to a magnetic field which varies with time as

B = B_{0} e^{- \frac{t}{τ}},

where

B_{0} and τ

are constants at time

t = 0

. If the resistance of the loop is

R

, then the heat generated in the loop after a long time

(t \to \infty)

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A uniform magnetic field is restricted within a region of radius,

r .

The magnetic field changes with time at a rate,

\frac{d \vec{B}}{d t}

. Loop one of radius

R > r

encloses the region,

r

and loop two of radius,

R

is outside the region of magnetic field as shown in the figure below. Then the emf generated is

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HARD

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A long solenoid of radius

R

carries a time

(t)

dependent current

I (t) = I_{0} t (1 - t)

. A ring of radius

2 R

is placed coaxially near its middle. During the time interval

0 \leq t \leq 1,

the induced current

(I_{R})

and the induced

E M F (V_{R})

in the ring change as:

EASY

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

Two sentences are given below and you are required to find the correct sentence which combines both the sentences.

Which is the correct combination of the given two sentences?

He is too tired. He could not stand.

HARD

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A conducting square frame of side

a

and a long straight wire carrying current

I

are located in the same plane as shown in the figure. The frame moves to the right with a constant velocity

V

. The e.m.f induced in the frame (when the centre of the frame is at a distance

x

from the wire) will be proportional to :
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MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

In the following sentence, a blank space with four options is given. Select whichever preposition or determiner you consider the most appropriate for the blank space.

These are the good rules to live _____.

HARD

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A metallic loop is placed in a uniform magnetic field $B$ with the plane of the loop perpendicular to $B .$ Under which condition (s) given an emf will be induced in the loop? "If the loop is .....

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A very long solenoid of radius

R

is carrying current

I (t) = k t e^{- α t} (k > 0),

as a function of time

(t \geq 0) .

Counterclockwise current is taken to be positive. A circular conducting coil of radius

2 R

is placed in the equitorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by:

EASY

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A long solenoid of diameter

0.1 m

has

2 \times 10^{4}

turns per meter. At the centre of the solenoid, a coil of

100

turns and radius

0.01 m

is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to

0 A

from

4 A

0.05 s

. If the resistance of the coil is

10 π^{2} Ω,

the total charge flowing through the coil during this time is

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

At time

t = 0

magnetic field of

1000 G a u s s

is passing perpendicularly through the area defined by the closed loop shown in the figure. If the magnetic field reduces linearly to

500 G a u s s,

in the next

5 s,

then induced

E M F

in the loop is:
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MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

The relation between the charge flow

ΔQ

through the circuit of resistance

r

and the change in the magnetic flux

{Δϕ}_{B}

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A planar loop of wire rotates in a uniform magnetic field. Initially, at

t = 0

, the plane of the loop is perpendicular to the magnetic field. If it rotates with a period of

10 s

about an axis in its plane then the magnitude of induced emf will be maximum and minimum, respectively at:

EASY

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A coil of cross-sectional area

A

having

n

turns is placed in a uniform magnetic field

B

. When it is rotated with an angular velocity

ω,

the maximum e.m.f. induced in the coil will be:

MEDIUM

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A metal disc of radius

100 cm

is rotated at a constant angular speed of

60 rad s^{- 1}

in a plane at right angles to an external field of magnetic induction

0.05 Wb m^{- 2}

. The emf induced between the centre and a point on the rim will be

HARD

Physics>Electricity and Magnetism>Electromagnetic Induction>Faraday's Laws of Induction

A circular insulated copper wire loop is twisted to form two loops of area

A

and

2 A

as shown in the figure. At the point of crossing the wires remain electrically insulated from each other. The entire loop lies in the plane (of the paper). A uniform magnetic field

\vec{B}

points into the plane of the paper. At

t = 0

, the loop starts rotating about the common diameter as axis with a constant angular velocity in the magnetic field. Which of the following options is/are correct?
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A random shaped conducting wire is moved in a uniform magnetic field as shown. Find motional emf induced across its ends at this instant for which its coordinates are mentioned. [v is along x-axis.]

Important Questions on Electromagnetic Induction

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A random shaped conducting wire is moved in a uniform magnetic field as shown. Find motional emf induced across its ends at this instant for which its coordinates are mentioned. [ $v$ is along x-axis.]