Let I be the current in the series circuit at any instant. Then voltage will be differ due to R, L and C.
Potential across inductance coil Inductance L is ahead of current by
potential across capacitor Capacitance C lags behind the current by
Where R = Resistance I = current
So using Pythagorean Theorem, we get
The effective resistance of series LCR circuit which opposes the flow of current is called Impedance. It is denoted by Z.
(i) Inductive LCR circuit
(ii) Capacitive LCR circuit
Clearly the circuit is purely resistive
The current and voltage are in same phase and the current is maximum. This is Resonance condition