The reactance of an AC circuit is zero. This means that the circuit contains
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → an inductor and a capacitor
The net reactance of a circuit containing inductance and capacitance is \( X = X_L-X_C \). It can be zero only if the inductive and capacitive reactances cancel, which is the condition of resonance:
\( \displaystyle X_L = X_C \Rightarrow \omega L = \frac{1}{\omega C} \Rightarrow \omega = \frac{1}{\sqrt{LC}} \)
So the circuit must contain both an inductor and a capacitor (operated at the resonant frequency).
NCERT (2026-27):
Summary – “… 8. In a RLC circuit, resonance phenomenon occur when \( X_L = X_C \) or \( \omega_0 = \frac{1}{\sqrt{LC}} \). For resonance to occur, the presence of both L and C elements in the circuit is a must. With only one of these (L or C ) elements, there is no possibility of voltage cancellation and hence, no resonance is possible.”