A small signal voltage `V(t)=V_(0)sin omegat` is applied across an ideal capacitor `C`:

Options

A. over a full cycle, the capacitor does not consume any energy form the voltage source
B. current `I (t)` is in phase with the voltage `V (t)`
C. Current `(I (t)` leads the voltage `V (t)` by `180^(@)`
D. current `I (t)` lags behind the voltage `V (t)` by `90^(@)`

Answer

A

Explanation

Voltage applied acorss an ideal capcaitor
`V = V_(0) sin omega t`
Through capacitor, current leads the applied e.m.f. by a phase angle of `90^(@)`
Average power over a complete cycle
`P = VI cos phi = VI cos 90^(@) =` Zero.
Choice (a) is correct.