Q. An average induced e.m.f. of $1V$ appears in a coil when the current in it is changed from $10A$ in opposite direction in $0.5\ sec$. Self-inductance of the coil is
A) $25\ mH$
B) $50\ mH$
C) $75\ mH$
D) $100\ mH$
Explanation
(a) $|e| = L\frac{di}{dt} \Rightarrow 1 = \frac{L \times \lbrack 10 - ( - 10)\rbrack}{0.5} \Rightarrow L = 25mH$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.