(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.

Explanation

### Solution

**(a) Derivation of the Average Power Consumed in a Series LCR Circuit:**

1. **Voltage and Current Representation:**
- The voltage across the LCR circuit can be represented as:
\[
V(t) = V_m \sin(\omega t)
...