Q. A current of 10 A in the primary coil of a circuit is reduced to zero. If the coefficient f mutual inductance is 3H and emf induced in secondary coil is 30 kV, time taken for the change of current is
A) $10^{3}\ $s
B) $10^{2}$ s
C) $10^{- 3}$ s
D) $10^{- 2}$ s
Explanation
(c) As $e = M\frac{di}{dt}$
$\therefore\ 30 \times 10^{3} = 3 \times \frac{10}{dt},$
$d = \ \frac{30}{30 \times 10^{3}} = 10^{- 3}\ $s
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.