Home
Class 12
PHYSICS
A conducting loop of radius R is present...

A conducting loop of radius R is present in a uniform magnetic field B perpendicular to the plane of the ring. If radius R varies as a function of time t, as `R =R_(0) +t`. The emf induced in the loop is

A

`2pi(R_(0)+t)B` clockwise

B

`pi(R_(0)+t)B` clockwise

C

`2pi(R_(0)+t)B` anticlockwise

D

zero

Text Solution

Verified by Experts

The correct Answer is:
C
Given`R=(R_0)+t`
`A=pi R^(2)=pi(R_(0)+t)^(2), (dA)/(dt) = 2 pi (R_(0)+t)`
therefore, emf induced in the loop is
`e=B(dA)/(dt) = 2 pi (R_(0)+t)B`
Since area is increasing, induced emf is in anticlockwise sense to oppose the chang in flux.
Promotional Banner

Topper's Solved these Questions

  • MISCELLANEOUS VOLUME 5

    CENGAGE PHYSICS ENGLISH|Exercise Multiple Correct|34 Videos

  • MISCELLANEOUS VOLUME 5

    CENGAGE PHYSICS ENGLISH|Exercise Linked Comprehension|84 Videos

  • MISCELLANEOUS VOLUME 3

    CENGAGE PHYSICS ENGLISH|Exercise True and False|3 Videos

  • NUCLEAR PHYSICS

    CENGAGE PHYSICS ENGLISH|Exercise ddp.5.5|14 Videos

Similar Questions

Explore conceptually related problems

A circular loop of radius R is kept in a uniform magnetic field pointing perpendicular into the plane of paper. When a current l flows in the loop, the tension produced in the loop is

The magnetic field perpendicular to the plane of a conducting ring of radius r changes at the rate. (dB)/(dt) . Then

A conducting ring is placed in a uniform magnetic field with its plane perpendicular to the field . An emf is induced in the ring if

The figure shows a non conducting ring of radius R carrying a charge q . In a circular region of Radius r , a uniform magnetic field B perpendicular to the plane of the ring varies at a constant rate (dB)/(dt)=beta . The torque on the ring is

A current carrying loop of radius R and mass 'm' is placed inside a uniform magnetic field an shown

The figure shows a conducting ring of radius R . A uniform steady magnetic field B lies perpendicular to the plane of the ring a circular region r (lt R) . If the resistance per unit length of the ring is lamda , then the current induced in the ring when its radius gets doubled is

A superconducting loop of radius R has self inductance L . A uniform & constant magnetic field B is applied perpendicular to the plane of the loop. Initially current in this loop is zero. The loop is rotated about its diameter by 180^(@) .Find the current in the loop after rotation.

A conducting ring of radius r and resistance R is placed in region of uniform time varying magnetic field B which is perpendicular to the plane of the ring. It the magnetic field is changing at a rate alpha , then the current induced in the ring is

A conducting loop (as shown) has total resistance R. A uniform magnetic field B=gammat is applied perpendicular to plane of the loop where gamma is a constant and t is time. The induced current flowing through loop is

A metal rod of resistance R is fixed along a diameter of a conducting ring of radius r. There is a magnetic field of magnitude B perpendicular to the plane of the loop. The ring spins with an angular velocity omega about its axis. The centre of the ring is joined to its rim by an external wire W. The ring and W have no resistance. The current in W is