A conducting circular loop is placed in a uniform magnetic field, $B = 0.25\ T$ with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of $1mms^{- 1}$. The induced e.m.f. when radius is $2cm$, is

Question

Dr. Abubacker · Accepted Answer

(c) $\phi = (B)\left( \pi r^{2} ight) \Rightarrow e = \frac{d\phi}{dt} = (B)(2\pi r)\left( \frac{dr}{dt} ight)$
$= (0.025)(2\pi)\left( 2 	imes 10^{- 2} ight)\left( 10^{- 3} ight) = \pi\ \mu V$

Q. A conducting circular loop is placed in a uniform magnetic field, $B = 0.25\ T$ with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of $1mms^{- 1}$. The induced e.m.f. when radius is $2cm$, is

Explanation

Reviewed by Dr. Abubacker

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