A resistor R, an inductor L and a capacitor C are connected in series to an oscillator of frequency n. If the resonant frequency is , then the current lags behind voltage, when
The current will lag behind the voltage when reactance of inductance is more than the reactance of condenser. Thus, ωL> 1wC or ω> 1√LC or n> 12π√LC or n> nr where nr= resonant frequency