Question

The Nyquist plot for the open-loop transfer function $G\left(s\right)$ of a unity negative feedback system is shown in the figure, if $G\left(s\right)$ has no pole in the right-half of s-plane, the number of roots of the system characteristic equation in the right-half of s-plane is

• A. $0$
• B. $1$
• C. $2$
• D. $3$

Answer 1

The correct option is A $0$

$N=0$
( 1 encirclement in CW direction and other in ACW)
$P=0$ (no pole in right half)
So,
$N=P-Z$
$Z=P-N=0$
$\therefore$ No roots on RH of s-plane