G(s) Question 1 An open-loop system with a unity feedback is used for motor speed control as shown in Figure 1(a). The open-loop response to a unit step input for G(s) when G.(s)-I is represented in Figure 1(b). 12 1 08 06 04 0.2 R(s) G(s) Ge(s) C(s) Figure 1(a) Step Response of G(s) 0 0 2 3 4 5 6 7 Time (seconds) Figure 1(b) (a) For G(s) and settling time. T. at G(s) = 1, (i) (ii) Sketch the root locus of the system represented by Figure 1(b) for 0 < K < x. The gain. K is adjusted until the current damping ratio. is decreased to 70% from its original value. On the same root locus plot, identify and properly label the position of K, its value and close-loop pole's (b) For Ge(s) 1/s and settling time, 7. at Gis) 1. (i) (ii) [10 marks] Re-sketch the root locus of the system represented by Figure 1(b) for < K < On the same root locus plot, identify and properly label the position of K, its value and close-loop pole's when the overall system is marginally stable. [10 marks]