This set of Control Systems Multiple Choice Questions & Answers (MCQs) focuses on “Time Response of Second Order Systems – III”.

1. Consider a system with transfer function G(s) = s+6/Ks^{2}+s+6. Its damping ratio will be 0.5 when the values of k is:

a) 2/6

b) 3

c) 1/6

d) 6

2. The output in response to a unit step input for a particular continuous control system is c(t)= 1-e^{-t}. What is the delay time Td?

a) 0.36

b) 0.18

c) 0.693

d) 0.289

3. What will be the nature of time response if the roots of the characteristic equation are located on the s-plane imaginary axis?

a) Oscillations

b) Damped oscillations

c) No oscillations

d) Under damped oscilaations

4. Which one of the following is the most likely reason for large overshoot in a control system?

a) High gain in a system

b) Presence of dead time delay in a system

c) High positive correcting torque

d) High retarding torque

5. The unit step response of a second order system is = 1-e^{-5t}-5te^{-5t} . Consider the following statements:

1. The under damped natural frequency is 5 rad/s.

2. The damping ratio is 1.

3. The impulse response is 25te^{-5t}.

Which of the statements given above are correct?

a) Only 1 and 2

b) Only 2 and 3

c) Only 1 and 3

d) 1,2 and 3

6. The peak percentage overshoot of the closed loop system is :

a) 5.0%

b) 10.0%

c) 16.3%

d) 1.63%

7. For the system 2/s+1, the approximate time taken for a step response to reach 98% of its final value is:

a) 1s

b) 2s

c) 4s

d) 8s

8. The loop transfer function of controller Gc(s) is :

a) 1+0.1s/s

b) -1+0.1s/s

c) –s/s+1

d) s/s+1

9. Consider a second order all-pole transfer function model, if the desired settling time(5%) is 0.60 sec and the desired damping ratio 0.707, where should the poles be located in s-plane?

a) -5+j4√2

b) -5+j5

c) -4+j5√2

d) -4+j7

10. Which of the following quantities give a measure of the transient characteristics of a control system, when subjected to unit step excitation.

1. Maximum overshoot

2. Maximum undershoot

3. Overall gain

4. Delay time

5. Rise time

6. Fall time

a) 1,3 and 5

b) 2, 4 and 5

c) 2,4 and 6

d) 1,4 and 5