Question

A magnetic dipole is placed in a uniform magnetic fields, B, the potential energy is minimum when dipole is

• A. Parallel to $B$
• B. Perpendicular to $B$
• C. Inclined at an angle of ${45}^{\circ }$ to $B$
• D. Anti-parallel to $B$

Answer 1

The correct option is A Parallel to $B$

Potential energy is given by
$U=M.B=-MBcos\theta$
Thus, potential energy is minimum when dipole is parallel to B.