Q. A magnet of magnetic moment $M$ is rotated through $360{^\circ}$ in a magnetic field $H$. The work done will be
A) $MH$
B) $2MH$
C) $2\pi MH$
D) Zero
Explanation
(d) $W = MB\left( \cos{\theta_{1} - \cos\theta_{2}} \right);\ \theta_{1} = 0{^\circ}$ and $\theta_{2} = 360{^\circ} \Rightarrow W = 0$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.