The polar plot of a transfer function passes through the critical point (-1,0). Gain margin is
A. Zero
B. -1dB
C. 1dB
D. Infinity
Answer:A
The polar plot of a transfer function passes through the critical point (-1,0). Gain margin is
A. Zero B. -1dB C. 1dB D. Infinity
Explanation: Gain margin of a polar plot passing through the critical point is zero.