1. The breakaway point  of the root locus from the real axis of a  closed loop control system G(s)H(s) is (GATE 1995)

G(s)H(s) = lies

a) Between -2 and origin

b) Between -2 and -5

c) Between -10 and -infinity

d)  At infinity

2) A unity feedback system has open loop transfer function  G(s)H(s)= . Its root locus plot intersects the jw axis at

a)

b) 

c) 

d) Does not intersect the jw axis

3) A unity feedback system has open loop transfer function  G(s)H(s)= . What is the maximum value of K for which the given open loop TF is stable enough?

a)

b) 6

c) 10

d) 6 

 

4) The value of K for which the unity feedback system

= crosses the imaginary axis is

a) 8

b) 16

c) 48

d)64

…….

 

** BODE PLOT QUESTIONS***

5) The Bode plot for the gain magnitude of a minimum phase system G(s) is shown in the figure. The transfer function G(s) is

a)

b)

c)

d)  

 

6) For a transfer function  . Maximum phase lead of the compensator is   (GATE EE-2000)

a) 52 deg at 4 rad/s

b) 52 deg at 10 rad/s

c) 55 deg at 12 rad/s

d) None of the above.