Q. A coil of area $100cm^{2}$ has 500 turns. Magnetic field of $0.1\ weber/metre^{2}$ is perpendicular to the coil. The field is reduced to zero in $0.1\ second$. The induced e.m.f in the coil is
A) 1 $V$
B) 5 $V$
C) 50 $V$
D) Zero
Explanation
(b) $e = - \frac{N\left( B_{2} - B_{1} \right)A\cos\theta}{\Delta t}$
$= - \frac{500 \times (0 - 0.1) \times 100 \times 10^{- 4}\cos 0}{0.1} = 5V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.