A uniform magnetic field of 3000G is established along the positive z-direction. A rect angular loop of sides 10 cm and 5 cm carries a current of 12A. What is the torque on the loop in different cases shown in the figure? What is the force on each case? Which case corresponds to stable equilibrium?

Explanation

use `tau = IA xx B ` and `F = Il xx B`
(a) `1.8 xx 10^(-2)` N m along - y direction
(b) same as in (a)
( c) ` 1.8 x 10^(-2) N` m along -x direction
( d) `1.8 xx 10^(-2) N` m at an angle of `240^@` with the +x direction
(e ) zero
( f) zero
Force is zero in each case. Case (e) corresponds to stable, and case (f) corresponds to unstable equilibrium.