Q. A magnetic dipole is placed in a uniform magnetic field. The net magnetic force on the dipole
A) Is always zero
B) Depends on the orientation of the dipole
C) Can never be zero
D) Depends on the strength of the dipole
Explanation
(a) A bar magnet having N-S pole, strength m and length 2I be placed in a uniform magnetic field of strength B making an angle $\theta$ with the direction of the magnetic field. Force on N-pole of the magnet=mB (along the direction of magnetic field B.)
Force on S-pole of the magnet $= mB$ (along the direction of magnetic field B.)
Force on S-pole of the magnet $= mB$ (opposite to the direction of magnetic field B).
Therefore, net magnetic force on the dipole is zero.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.