A series LCR circuit is driven by an alternating source of fixed amplitude
PHYSICS · Multi-part · CBSE · Physics · Alternating Current · Alternating Current
Problem
A series LCR circuit is driven by an alternating source of fixed amplitude. You are asked to analyse how the current–frequency (I–ω) resonance curve changes when only the resistance of the circuit is varied.
(i) Define the bandwidth of a series LCR circuit in terms of the resonance curve.
(ii) Explain qualitatively, with reasons, how increasing the resistance R affects (a) the maximum value of current at resonance and (b) the width of the resonance curve.
(iii) On the same set of axes, sketch rough resonance curves for two circuits that are identical except that R1<R2. Label the curves clearly and mark the half-power points.
(iv) Which circuit, the one with R1 or with R2, has the larger quality factor Q? Justify your answer on the basis of your sketch.