An inductor of 0.5 mH, a capacitor of 20 μF and resistance of 20 Ω are connected in series with a 220 V AC source. If the current is in phase with the emf, the amplitude of current is √x A. The value of x is:
Physics · Circular Motion
JEE Mains 31 January 2023 Shift 1 Morning Shift

Question

An inductor of 0.5 mH, a capacitor of 20 μF and resistance of 20 Ω are connected in series with a 220 V AC source. If the current is in phase with the emf, the amplitude of current is √x A. The value of x is:

Physics · Circular Motion

G1 Physics · Accepted Answer

Current is in phase at resonance, so Z = R = 20 Ω. I(rms)=220/20=11 A. Peak current I(max)=11√2 A = √242 A. Hence x=242.