Question

A conducting circular loop is placed in a uniform magnetic field, B = 0.025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mm s ^-1. The induced emf when the radius is 2 cm, is

(a) 2πμV

(b) πμV

(c)  π/2 μV

(d) 2 μ V

Answer 1

Correct option  (b) πμV

Explanation:

Here,

Magnetic field, B = 0.025 T

Radius of the loop, r = 2 cm = 2 x 10^-2 m

Constant rate at which radius of the loop shrinks,

Magnetic flux linked with the loop is

The magnitude of the induced emf is