In a negative unit feedback system, the control body is of PD (proportion + derivative) type and its proportion gain is Kp and derivative gain is Kd. The supervised system is of type 0 and has two first-order elements with a time constant of 4 s. According to this;
a) Find the unit step steady-state error for the system Kp=10 and Kd = 2.
b) Find the Kd value or values that ensure the stable operation of the control system for Kp = 10.
c) Adding integral effect to this system instead of derivative effect at the same proportion gain (Kp=10)
Calculate the steady state error for unit step input and integral gain Ki = 8.