# Time Response of Control Systems

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

1. The transient response, yt(t), of a system becomes ____ as t tends to infinity.
a) 0
b) 1
c) Infinity
d) Undefined

2. The steady state value of a system is _____ it’s a transient response.
a) dependent on
b) independent of
c) greater than
d) not observable from

3. Delay time is the time required by a system to reach a quarter of its steady state value.
a) True
b) False

4. For non-unity feedback system, the error is calculated with respect to the reference signal.
a) True
b) False
.

5. What is the output of the following code?

```>>p=[0 1];
>> q=[ 1 -1 0];
>> step(p,q)```

a) An unstable response
b) A stable response
c) A marginally stable response
d) A marginally unstable response

6. Which of the following command will reveal the damping ratio of the system?
a) damp()
b) damp[]
c) damping{}
d) dr()

7. What is the output of the following code?

```>>p=[ 1 0 1];
>> q=[  -1 1];
>> step(p,q);```

a) An unstable step response
b) A stable step response
c) Error
d) A marginally unstable response

8. What is the output of the following code?

`tf({1},{1 1})`

a) Error
b) 1/s+1
c) s+1/1
d) 1/s

9. If the damping factor is zero, the unit-step response is
a) Purely sinusoidal
b) Ramp function
c) Pulse function
d) Impulse function

10. What is the output of the following code?

`impulse([1],[1 1])`

a) e-t*u(t)
b) e-t*u(-t)
c) e-t*u(t)
d) e+t*u(t)

11. If the damping ratio is equal to 1, a second-order system is _________
a) having maginary roots of the characteristic equation
b) underdamped
c) critically damped with unequal roots
d) critically damped with equal roots

12. From the following graphs of the generalized transfer function 1/s+a, which plot shows a transfer function with a bigger value of a?

a) Blue plot
b) Red plot
c) Yellow plot
d) Purple plot

13. From the following graphs of the generalized transfer function 1/as2, which plot shows the transfer function for a higher a?

a) Blue
b) Red
c) Yellow
d) Purple

14. If the damping factor is less than the damping factor at critical damping, the time response of the system is ___________
a) Underdamped
b) Overdamped
c) Marginally damped
d) Unstable

15. The steady state error of the system with a forward path transfer function G(s)=13(s-1)/(s-1) and with a parabolic input is _______
a) Infinite
b) 0
c) -Infinite
d) Undefined

16. For a step response of the system 1/s2+1, the maximum overshoot is __________
a) 1
b) 0
c) Infinite
d) 2

17. What is the gain of the system derived from the following code?

`tf[1,100]`

a) 1/100
b) s/100
c) 1/100s
d) Error

18. What is the output of the following code?

`step(impulse(1,[1 0]))`

a) A ramp function
b) A parabolic function
c) A step function
d) Error

19. What is the output of the following code?

```r.DampingRatio = 0;
overshoot = getOvershoot(r);```

a) 100
b) 0
c) 1
d) Error

20. Which of the following command gives the step response characteristics of a control system?
a) stepinf()
b) stepinfo()
c) stepinfo[]
d) step()

21. Which of the following command generates the impulse response of a system which has more zeros than poles?
a) impulse()
b) impulse[]
c) impulse{}
d) No such command

22. Which of the following command generates the transfer function of a system?
a) tf()
b) tf[]
c) tf{}
d) No such command

23. What is the output of the following code?

`step([1],[1 0 0])`

a) A parabola
b) A ramp function
c) A step function
d) An impulse function

24. The time constant of a system is ________
a) equal to the damping constant
b) inverse of the damping constant
c) twice the damping constant
d) half of the damping constant

25. If the natural frequency of a system increases, the rise time ________
a) Increases
b) Decreases
c) Doubles
d) Halves

26. The settling time is a measure of _________
a) The speed of reaching stead state
b) The speed of reaching maximum overshoot
c) The speed of reaching second overshoot
d) Nothing

27. If the poles of a system transfer function are equal and imaginary, the system is ________
a) Undamped
b) Critically damped
c) Overdamped
d) Negatively damped

28. For negative damping, the system is unstable.
a) True
b) False

29. An undamped system is stable.
a) True
b) False