Question

In the circuit given below, M = 1. The resonant frequency is _______________

(a) 145.3 Hz

(b) 0.1453 Hz

(c) 1.453 Hz

(d) 14.53 Hz

I got this question during an online interview.

This intriguing question comes from Advanced Problems on Filters in chapter Filters and Attenuators of Network Theory

Answer 1

Correct option is (d) 14.53 Hz

Easy explanation: IEQ = L1 + L2 + 2M

LEQ = 5 + 5 + 2 × 1

= 10 + 2 = 12 H

∴ FO = \(\frac{1}{2π\sqrt{LC}}\)

= \(\frac{1}{2π\sqrt{12 × 0.1}}\)

= 0.1453 Hz.