A uniform magnetic field B of 0.3 T is along the positive Z-direction. A rectangular loop (abcd) of sides 10 cm `xx` 5 cm carries a current I of 12 A. Out of the following different orientations which one corresponds to stable equilibrium?

Options

A.
B.
C.
D.

Answer

D

Explanation

Magnetic potential energy of the dipole in a magnetic field, `U=-vecMvecB`
As M and B are same in each case (in magnitude)
for stable equilibrium, potential energy should be minimum. Minimum potential energy is possible if `vecM` and `vecB` are in same direction. So option (d) is correct.