Question
The figure shows a series LCR circuit with L = 5.0 H, C = 80 mF, R = 40 W connected to a variable frequency 240V source. Calculate. 
(i) The angular frequency of the source which drives the circuit at resonance.
(ii) The current at the resonating frequency.
(iii) The rms potential drop across the capacitor at resonance.
Solution
Given a series LCR circuit,
i) At resonance, angular frequency is given by,
ii) Current at resonating frequency is given by,
iii) RMS potential drop across the capacitor at resonance is given by, 
