NEET2016PhysicsAlternating CurrentActual
A small signal voltage V t = V 0 sin ⁡ ω t is applied across an ideal capacitor C :
Options
- ACurrent I(t), lags voltage V(t) by 90 o
- BOver a full cycle the capacitor C does not consume any energy from the voltage source
- CCurrent I(t) is in phase with voltage V(t).
- DCurrent I(t) leads voltage V(t) by 180 o
Correct answer
B. Over a full cycle the capacitor C does not consume any energy from the voltage source
Step-by-step solution
In capacitor current leads the voltage by ϕ = π 2 phase. Average power dissipated in AC circuit is given by P a v = V r m s I r m s cos ϕ In capacitor ϕ = π 2 so cos π 2 is zero.