Determine whether the systems with these transfer functions are stable, marginally stable or unstable.

Question

Sketch a root locus for each of the diagrams in Figure E-14. The diagrams show the poles and zeros of the loop transfer function of a feedback system.

Answer 1

For each system indicate whether it will be unstable at some finite positive value of the gain constant K

Answers:
A Unstable at some finite positive K
B Stable for all finite positive K
C Stable for all finite positive K
D Unstable at some finite positive K
E Stable for all finite positive K
F Unstable at some finite positive K
G Unstable at some finite positive K
H Stable for all finite positive K
I Stable for all finite positive K