Can you have an `AC` series circuit in which there is a phase difference of (a) `180^0` (b) `120^0` between the emf and the current?

An emf of V= V_0sin omegat is applied on a series LCR circuit. IF there is no phase difference between the voltage and current then,

(a) Deriver and expression for the average power consumed in a series LCR circuit connected to a.c., source in which the phase different between the voltage and the current in the circuit is phi . (b) Define the quality factor in an a.c. circuit. Why should the quality factor have high value in receiving circuits ? Name the factors on which it depends.

The power factor of an a.c. circuit is 0.5. what will be the phase difference between voltage and the current?

In a LCR series circuit, if the phase difference between applied voltage and current is zero then