Question

The critical value of gain for the system is 40. The system is operating at a gain of 20. The gain margin of the system is :

(a) 2 dB

(b) 3 dB

(c) 6 dB

(d) 4 dB

Answer 1

Correct choice is (c) 6 dB

To explain I would say: G.M. =Kmarginal/Kdesire

Kmarginal =40

Kdesire = 20

G.M. =2

G.M. (dB) = 6dB.