Question

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 π / 2
• B. Current is ahead of e.m.f. by π / 2
• C. Current lags behind e.m.f. by π
• D. Current is ahead of e.m.f. by π

Answer 1

Answer: (B)

Current is ahead of e.m.f. by π / 2

Answer 2

For purely capacitive circuit $e = e _ { 0 } \sin \omega t$

$i = i _ { o } \sin \left( \omega t + \frac { \pi } { 2 } \right)$ i.e. current is ahead of emf by $\frac { \pi } { 2 }$