Q. A magnetic dipole is placed in two perpendicular magnetic fields $\overrightarrow{B}$ and $\overrightarrow{H}$ and is in equilibrium taking angle $\theta$ with $\overrightarrow{B}$. Then
A) $B = H$
B) $B\ cos\theta = H\sin\theta$
C) $B\sin{\theta = H\cos\theta}$
D) $B = H\tan\theta$
Explanation
(c) As $\theta$ is with $B$, therefore according to tangent law,
$H = B\tan{\theta = \frac{Bsin\theta}{cos\theta}}\ or\ B\ sin\theta = Hcos\theta$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.