A unity feedback system that uses proportional - integral (PI) control is shown in the figure.

The stability of the overall system is controlled by tuning the 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 $\_\_\_\_$

The loop transfer function of a negative feedback system is

$$ G(s) H(s)=\frac{K(s+11)}{s(s+2)(s+8)} $$

The value of $K$, for which system is marginally stable, is $\_\_\_\_$ .

Consider p(s) = s³ + $${a_2}$$s² + $${a_1}$$s + $${a_0}$$ with all real coefficients. It is known that its derivative p'(s) has no real roots. The number of real roots of p(s) is

The Nyquist stability criterion and the Routh criterion both are powerful analysis tools for determining the stability of feedback controllers. Identify which of the following statements is FALSE.