Question

In a series RLC circuit that is operating above the resonant frequency, the current

• A. lags the applied voltage
• B. leads the applied voltage
• C. is in phase with the applied voltage
• D. is zero

Answer 1

Answer: (A)

lags the applied voltage

Capacitive reactance is given by $X_C=\frac{1}{wC}$
Inductive reactance is given by $X_L=wL$
At resonance, $X_L=X_C$ $⟹wL=\frac{1}{wC}$
But a frequency higher than resonance frequency, $X_L>X_C$
So the circuit behaves as a inductive circuit at a frequency higher that resonant frequency and the current lags behind the voltage in an inductive circuit.
Thus option A is correct.