An a.c. source of voltage

(i) An a.c. source of voltage V = V0 sin cot is connected to a series combination of L, C and R. Use the phasor diagram to obtain expressions for impedance of the circuit and phase angle between voltage and current. Find the condition when current will be in phase with the voltage. What is the circuit is this condition called ?
(ii) In a series LR circuit XL = R and power factor of the circuit is P1. When capacitor with capacitance C