A circular loop of radius R carries a current I. Another circular loop of radius `r(ltltR)` carries a current i and is placed at the centre of the larger loop. The planes of the two circles are at right angle to each other. Then the torque acting on the smaller loop.

Options

A. `(mu_0pi iIR^2)/(2R)`
B. `(mu_0pi iIr)/(2R)`
C. `(mu_0pi iIR)/(2r)`
D. `(mu_0pi iIr^2)/(2R)`

Answer

D