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 mms-1. The induced emf when the radius is 2 cm is
1
2 μV
2
2 πμV
3
πμV
4
\(\frac{\pi }{2}\mu V\)