The system with the open loop transfer function G(s) H(s) =1/s(s^2+s+1) has the gain margin of :
A. -6 dB
B. 0 dB
C. 3.5 dB
D. 6 dB
Answer:B
The system with the open loop transfer function G(s) H(s) =1/s(s^2+s+1) has the gain margin of :
A. -6 dB B. 0 dB C. 3.5 dB D. 6 dB
Explanation: Gain margin is calculated at phase cross over frequency where the phase is 180°.