In a series LCR circuit at resonance, the impedance is: MCQ with Answer and Explanation

In a series LCR circuit at resonance, the impedance is:
A. Zero
B. Infinite
C. Maximum
D. Minimum
Answer: Option D
Solution (By JKExamLibrary)
At resonance frequency ω₀ = 1/√(LC), inductive reactance X_L = ωL equals capacitive reactance X_C = 1/(ωC), so they cancel. Impedance Z = √[R² + (X_L - X_C)²] = R, which is minimum (since R is the only remaining component). Current is maximum at resonance. Memory tip: 'LCR resonance: Z_min = R, I_max, purely resistive'. This AC circuit concept is frequently tested in competitive exams. Always distinguish series resonance (Z min) from parallel resonance (Z max) behavior.

This question belongs to: Science Physics

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