Q. A current loop in a magnetic field -
A) experiences a torque whether the field is uniform or non-uniform in all orientations
B) can be in equilibrium in one orientation
C) can be in equilibrium in two orientations, both the equilibrium states are unstable
D) can be in equilibrium in two orientations, one stable while the other is unstable
Explanation
[Solution from source] Torque on a loop is τ = m × B, which is zero when the magnetic moment is parallel or antiparallel to B. The parallel position (minimum energy) is stable and the antiparallel position (maximum energy) is unstable. A loop does not feel a torque in every orientation. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.