A conducting circular loop is placed in a uniform magnetic field, B = .025 T with its e plane perpendicular to the loop The radius of the loop is made to shrink at a constant rate of 1 $mms^{–1}$. The induced e.m.f. when the radius is 2 cm, is –

Question

( A ) $\frac{\pi}{2}\mu V$
( B ) $\pi \mu V$
( C ) $2\pi \mu V$
( D ) $2\mu V$