Gate 2019: Control System Quiz 8

The pole-zero and the Nyquist plot of the loop transfer function G(s)H(s) of a feedback system is shown below:


For these systems

Consider a unity feedback System having an open-loop transfer function

For k=1 The gain margin is 28dB.When gain margin is 20 dB, K will be equal to

The open loop transfer function of a system is

The Nyquist plot for this system is

The polar plot of an open loop stable system is shown below. The closed loop system is

The frequency response of G(s) = 1/[s(s + 1) (s+ 2)] plotted in the complex G(jω) plane (for 0 < ω < ∞) is