Q. An alternating $e$.m.f. is applied to purely capacitive circuit. The phase relation between $e$.m.f. and current flowing in the circuit is or In a circuit containing capacitance only
A) $e$.m.f. is ahead of current by $\pi/2$
B) Current is ahead of $e$.m.f. by $\pi/2$
C) Current lags behind $e$.m.f. by $\pi$
D) Current is ahead of $e$.m.f. by $\pi$
Explanation
(b) For purely capacitive circuit $e = e_{0}\sin{\omega t}$
$i = i_{0}\sin\left( \omega t + \frac{\pi}{2} \right),i.e.,$ current is ahead of $e$mf by $\frac{\pi}{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.