Question

Find the resonant frequency in the ideal parallel LC circuit shown in the figure.

(a) 7.118

(b) 71.18

(c) 711.8

(d) 7118

The question was posed to me by my school principal while I was bunking the class.

This interesting question is from Parallel Resonance topic in division Resonance & Magnetically Coupled Circuit of Network Theory

Answer 1

Correct choice is (d) 7118

For explanation I would say: The expression for resonant frequency is fr = 1/(2π√LC). Given L = 50mH and C = 0.01uF. On substituting the given values in the equation we get the resonant frequency = 1/(2π√(50×10^-3)×0.01×10^-6))=7117.6 Hz.