Question

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 \( n_r \), then the current lags behind voltage when

• A. \( n = 0 \)
• B. \( n<n_r \)
• C. \( n = n_r \)
• D. \( n>n_r \)

Hint:

In an LC circuit, current lags behind voltage when the circuit is inductive (\( n<n_r \)).

Answer 1

The Correct Option is B

At resonance, the impedance of the circuit is minimized, and the voltage and current are in phase. When \( n<n_r \), the circuit behaves inductively, and the current lags behind the voltage.

Step 2: Conclusion.
The current lags behind the voltage when \( n<n_r \), corresponding to option (b).