GATE EC 2021 Set 1 Q48 — Control Systems

A unity feedback system that uses proportional-integral ($\text{PI}$) control is shown in the figure.

The stability of the overall system is controlled by tuning the $\text{PI}$ control parameters $K_{P}$ and $K_{I}$. The maximum value of $K_{I}$ that can be chosen so as to keep the overall system stable or, in the worst case, marginally stable (rounded off to three decimal places) is ___________________