# GATE Questions & Answers of Routh-Hurwitz and Nyquist Criteria

## What is the Weightage of Routh-Hurwitz and Nyquist Criteria in GATE Exam?

Total 3 Questions have been asked from Routh-Hurwitz and Nyquist Criteria topic of Control Systems subject in previous GATE papers. Average marks 1.67.

Loop transfer function of a feedback system is $G\left(s\right)H\left(s\right)=\frac{s+3}{{s}^{2}\left(s-3\right)}$ Take the Nyquist contour in the clockwise direction. Then, the Nyquist plot of $G\left(s\right)H\left(s\right)$ encircles $-1+j0$

The open loop transfer function of a unity feedback control system is given by

The closed loop system will be stable if,

Nyquist plot of two functions  ${G}_{1}$(s) and ${G}_{2}$(s) are shown in figure.

Nyquist plot of the product of ${G}_{1}$ (s) and ${G}_{2}$(s) is