A conducting circular loop is placed in a uniform magnetic

A conducting circular loop is placed in a uniform magnetic field of 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is

Induced emf in the loop is given by

e = - B.	dA
	dt

where A is the area of the loop.

e = - B.	d	(π r²) = - Bπ2r	dr
	dt		dt

r = 2cm = 2 × 10^–2 m
dr = 2 mm = 2 × 10^–3
m dt = 1s

e = - 0.04 × 3.14 × 2 × 2 × 10^-2 ×	2 × 10^-3	V
	1

= 0.32 π × 10^–5 V
= 3.2 π ×10^–6 V
= 3.2 π μV