The phenomenon of resonance in an LCR circuit occurs when: MCQ with Answer and Explanation

The phenomenon of resonance in an LCR circuit occurs when:
A. Resistance is zero
B. Inductive reactance equals capacitive reactance
C. Impedance is maximum
D. Frequency is zero
Answer: Option B
Solution (By JKSSB Mock Tests)
Resonance in series LCR circuit occurs when X_L = X_C, i.e., ωL = 1/(ωC) ⇒ ω = 1/√(LC). At this frequency, impedance is minimum (Z=R), current maximum, and circuit is purely resistive. Memory tip: 'Resonance: X_L = X_C; ω₀ = 1/√(LC); series: Z_min, parallel: Z_max'. This AC circuit concept is frequently tested in competitive exams. Always distinguish series and parallel resonance conditions; competitive exams often test series LCR resonance fundamentals.

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