Step 1: Understanding the Concept:
Resonance in an AC circuit occurs when the inductive reactance (\(X_L\)) equals the capacitive reactance (\(X_C\)).
Step 2: Detailed Explanation:
For resonance to occur, the circuit must contain both an inductor (L) and a capacitor (C). At resonance, \(X_L = X_C\), the impedance is minimum (purely resistive), and the current is maximum for a series LCR circuit. A circuit with only L and R, or only C and R, or only L, or only C does not exhibit a resonance phenomenon where the reactance cancels out.
Step 3: Final Answer:
Resonance occurs in a circuit containing an inductor and a capacitor.