Q.
A coil $PQRS$ carrying a current $i$ ampere is placed in a powerful horse shoe magnet $NS$ of uniform magnetic field $\overrightarrow{B}$ figure. If $A$ is the area of the coil and $\theta$ is the inclination of the plane of the coil with the magnetic field in equilibrium, then the deflecting couple will be
A) $BiA\cot\theta$
B) $BiA\cos\theta$
C) $BiA{cosec}\theta$
D) $BiA\sin\theta$
Explanation
(b) Deflecting couple = torque on the loop = $BiA\cos{\theta.}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.