If N is the number of encirclements of the (-1, j0) point made by the Nyquist plot, Z is the number of right half poles of the closed-loop transfer function and P is the number of open-loop poles in the right-hand side of s-plane then consider the following statements.
a. For closed loop stability, Z = 0
b. For open loop stability, P = 0
The correct statement is1
a only
2
b only
3
None of a & b
4
Both a & b