Q. An e.m.f. of $100\ millivolts$ is induced in a coil when the current in another nearby coil becomes $10\ ampere$ from zero in $0.1\ second$. The coefficient of mutual induction between the two coils will be
A) $1\ millihenry$
B) $10\ millihenry$
C) $100\ millihenry$
D) $1000\ millihenry$
Explanation
(a) Induced $e.m.f.\ e = M\ \frac{di}{dt} \Rightarrow 100 \times 10^{- 3} = M\left( \frac{10}{0.1} \right)$
$\therefore M = 10^{- 3}H = 1\ mH$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.