Question

A series RLC circuit has R = 50 Ω, L = 0.01 H and C = 0.04 × 10^-6 F. System voltage is 100 V. The frequency, at which the maximum voltage appears across the capacitor, is?

(a) 5937.81 Hz

(b) 7370 Hz

(c) 7937.81 Hz

(d) 981 Hz

This question was addressed to me in an online quiz.

The origin of the question is Problems of Series Resonance Involving Frequency Response of Series Resonant Circuit in chapter Resonance & Magnetically Coupled Circuit of Network Theory

Answer 1

Right option is (c) 7937.81 Hz

Explanation: Frequency fc at which VC is maximum fc = \(\frac{1}{2π}\Big[\frac{1}{0.01×0.01×10^{-6}} –  \frac{50×50}{2×0.01×0.01}\Big]^{0.5}\)

So, fc = 7937.81 Hz.