Electrical Engineering: Control system MCQ

In the given figure, plant G_p(s) = 2.2/[(1+0.1s)(1+0.4s)(1+1.2s)] and compansator 

The external disturbance input is D(s). It is desired that when the disturbance is a unit step, the steady -steady error should not exceed 0.1 unit. The minimum value of k is____

consider a closed-loop system as shown. G_P(s) =14.4 / [s(1+0.1s)] is the plant transfer function and G_c(s)=1 is the compensator. For a unit-step input, the output response has damped oscillations. The damped natural frequency is ____ rad/s.

Let p(z) =z³ + (1+j)z² + (2+ j)z +3 , where z is a complex number. Which one of the following is true?

The pole-zero plots of three discrete-time systems P, Q and R on the z-plane are shown below.

Which one of the following is TRUE about the frequency selectivity of these systems?

Let a causal LTI system be characterized by the following differential equation, with initial rest condition

Where, x(t) and y(t) are the input and output respectively. The impulse response of the system is (u(t) is the unit step function)