Q.

A conducting circular loop is placed in a uniform magnetic field of 0.4 T with its plane perpendicular to the field. Somehow, the radius of the loop starts expanding at a constant rate of 1 mm/s. The magnitude of induced emf in the loop at an instant when the radius of the loop is 2 cm will be _________ μV.              [2023]


Ans.

(50)

drdt=10-3 m/s

dAdt=2πrdrdt

ε=|-dϕdt|=|BdAdt|

                      =0.4×2×π×2×10-2×10-3 V

                       =16πμV=50.24 μV