Question

The below diagram shows the pole-zero plot of a continuous time system

The system is stable and non - causal for the ROC

• A. Re{s} >2
• B. -3<Re{s} <-2
• C. -2 <Re{s} <2
• D. Re{s} <-2

Answer 1

The correct option is C -2 <Re{s} <2

For an LTI system to be stable, the ROC of the system function must include the imaginary $\left(j\omega \right)$ axis.
Here the only ROC which contains imaginary axis is -2 < Re{s} <2
An LTI system is causal, if ROC is to the right side of right most pole.
$\therefore$ system is non -causal for -2<Re{s}< 2