Q. In a coil of self inductance $0.5\ henry$, the current varies at a constant rate from zero to $10\ amperes$ in $2\ seconds$. The e.m.f. generated in the coil is
A) $10\ volts$
B) $5\ volts$
C) $2.5\ volts$
D) $1.25\ volts$
Explanation
(c) $\frac{\mathrm{\Delta}i}{\mathrm{\Delta}t} = \frac{10}{2} = 5A/\sec \Rightarrow e = L\frac{\mathrm{\Delta}i}{\mathrm{\Delta}t} = 0.5 \times 5 = 2.5\ volts$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.