A small signal voltage V(t) = ``V_0 ``sin``\omega``t is applied
across an ideal capacitor C :-
(1) Current I (t), lags voltage V(t) by 90°.
(2) Over a full cycle the capacitor C does not
consume any energy from the voltage source.
(3) Current I (t) is in phase with voltage V(t).
(4) Current I (t) leads voltage V(t) by 180°.