Time Response Analysis MCQ

31. A unity feedback control system has

$G(s)=\frac{K}{s^2(1+sT)}$

The order and type of the closed-loop system will be

  1. 3 and 1
  2. 2 and 3
  3. 3 and 2
  4. 3 and 3
Answer
Answer. c

32. The open-loop transfer function of a control system is $\frac{10}{s+1}$. The steady-state error due to unit step input signal when operated as a unity feedback system is

  1. 1/11
  2. 0
  3. 10
Answer
Answer. b

33. The impulse response of a linear system is e-t , t > 0. The corresponding transfer function is

  1. $\frac{s}{s+1}$
  2. $\frac{1}{s}$
  3. $\frac{1}{s+1}$
  4. $\frac{1}{s(s+1)}$
Answer
Answer. c

34. A unity feedback system has a forward path transfer function

$G(s)=\frac{K}{s(s+8)}$

where K is the gain of the system. The value of K, for making this system critically damped, should be

  1. 8
  2. 4
  3. 32
  4. 16
Answer
Answer. d

35. A system has the following transfer function:

$G(s)=\frac{1}{s^2+0.1s+1}$

If step input is applied to this system, then its settling time within 5% tolerance band will be

  1. 40 sec
  2. 60 sec
  3. 10 sec
  4. 20 sec
Answer
Answer. b

36. A second-order control system exhibits 100% overshoot. Its damping coefficient is

  1. greater than 1
  2. less than 1
  3. equal to 1
  4. equal to 0
Answer
Answer. d

37. Given a unity feedback system with $G(s)=\frac{K}{s(s+4)}$ . The value of K for damping ratio of 0.5 is

  1. 2
  2. 4
  3. 16
  4. 1
Answer
Answer. c

38. Consider a unity feedback control system with open-loop transfer function

$G(s)=\frac{K(s+1)}{s(s+2)(s+3)}$

The steady-state error of the system due to a unit step input is

  1. 6/K
  2. K/6
  3. zero
Answer
Answer. d

39. A transfer function has a zero at s = -1 and poles at s = -1 ± j1. The multiplier being unity, if the input is unit step function, the steady-state response is given by

  1. 2∠90°
  2. 2∠0°
  3. 1∠0°
  4. 0.5∠0°
Answer
Answer. d

40. What will be the type of the system, if the steady-state performance of control system yields a non-zero finite value of the velocity error constant?

  1. type-1
  2. type-0
  3. type-3
  4. type-2
Answer
Answer. a