The open-loop transfer function of a control system is as follows:

Determine the integral time constant \(\left(T_{I}ight.\) ) for a proportional-integral-derivative (PID) controller in Ziegler-Nichols's method.

1) \(\frac{\pi}{2}\)
2) \(\pi\)
3) \(\frac{3 \pi}{2}\)
4) \(2 \pi\)

G(s)= k s(s1)