3 views

Common Data for Questions 53 and 54:

The Nyquist plot of a stable transfer function $G(s)$ is shown in the figure. We are interested in the stability of the closed loop system in the feedback configuration shown.

Which of the following statements is true?

1. $G(s)$ is an all-pass filter
2. $G(s)$ has a zero in the right-half plane
3. $G(s)$ is the impedance of a passive network
4. $G(s)$ is marginally stable