Q. In the following figure, the magnet is moved towards the coil with a speed $v$ and induced $emf\ e$. If magnet and coil recede away from one another each moving with speed $v$, the induced $emf$ in the coil will be
A) $e$
B) $2e$
C) $e/2$
D) $4e$
Explanation
(b) $\left( \frac{d\phi}{dtr} \right)_{In\ first\ case} = e$
$\left( \frac{d\phi}{dt} \right)_{relative\ velocity\ 2v} = 2\left( \frac{d\phi}{dt} \right)_{I\ case} = 2e$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.