 # Control Systems MCQs

A Control system is a system of devices that are used to manage, command, direct, or regulate the other devices’ behaviours to achieve the desired result. A control system can achieve this with the help of control loops, which are a process designed to maintain a process variable at the desired set point.

## MCQs on Control Systems

Solve Control Systems Multiple-Choice Questions to prepare better for GATE. Learn more about Control Systems and Control Systems MCQs by checking notes, mock tests, and previous years’ question papers. Gauge the pattern of MCQs on Control Systems by solving the ones that we have compiled below for your practice:

## Control Systems Multiple-Choice Questions

1. In the block diagram given below, G2=10/s+1, G1=10/s, H2=1, and H1=s+3.

The overall transfer function here would be given by:

a. 100/11s² + 31s + 100

b. 10/11s² + 31s + 10

c. 100/11s² + 31s

d. 100/11s² + 31s +10

Answer: (a) 100/11s² + 31s +100

2. Any control system that has excessive noise would most likely suffer from:

a. Oscillations

b. Vibrations

c. Loss of gain

d. Saturation in the amplifying stages

Answer: (d) Saturation in the amplifying stages

3. Which of these is the most common hydraulic fluid?

a. Gel

b. Water

c. Synthetic fluid

d. Mineral oil

4. A given control system yields a 0.20 steady-state error for a unit step input. We cascade a unit integrator to this system and then apply unit ramp input to this modified system. For this modified system, what would be the actual value of steady-state error?

a. 0.20

b. 0.10

c. 0.25

d. 0.15

5. With a feedback system, the transient response would:

a. Decays quickly

b. Decays slowly

c. Rises quickly

d. Rises slowly

Answer: (a) Decays quickly

6. We can apply the standard test signal to give output to:

a. Time-Invariant Systems

b. Time-Variant Systems

c. Non-Linear Systems

d. Linear Systems

Answer: (d) Linear Systems

7. What would be the intersection of the asymptotes of the root loci of a given system with a transfer function G(s)H(s) = K/s(s+1)(s+3) with an open-loop?

a. 1.33

b. 1.44

c. -1.33

d. -1.44

8. A system becomes ____________ as and when the polar plot would move toward the (-1, 0) point.

a. Marginally Stable

b. Unstable

c. Stable

d. Conditionally Stable

9. In the Nyquist plot, the unit circle would transform into 0dB line of the Bode diagram’s amplitude plot at:

a. Any Frequency

b. High Frequency

c. Low Frequency

d. 0 Frequency

Answer: (a) Any Frequency

10. The steady-state error is specified (usually) in terms of:

a. Damping Factor

b. Bandwidth

c. Error Constants

d. Speed of Response

Answer: (c) Error Constants

11. In a unity feedback system, the control transfer function with an open loop is given by:

G(s) =K/(s+2)(s+4)(s^2+6s+25)

In the closed-loop system, what should be the value of K that leads to sustained oscillations?

a. 1190

b. 990

c. 790

d. 590

12. What would be the homogeneous solution of the following:

y(n) -9/16y(n-2) = x(n-1)

a. C1-(3/4)n-1+C2(3/4)n-1

b. C1(3/4)n+C2(3/4)-n

c. C1-(3/4)n

d. C1(3/4)n

13. An LTI system’s transfer function is given as 1/(s+1). Here, what would be the steady-state value of any unit-impulse response?

a. Infinite

b. 2

c. 1

d. 0

14. What are the points at which the derivatives of all state variables happen to be zero?

a. Nonsingular Points

b. Singular Points

c. Zeros

d. Poles

Answer: (b) Singular Points

15. An externally introduced signal that affects the controlled output is known as a:

a. Stimulus

b. Feedback

c. Gain Control

d. Signal

16. What are the mediums responsible for the transportation lag?

a. Belt Conveyors

b. Lines

c. Pipes

d. All of the above

Answer: (d) All of the above

17. How are the robots used in automobile plants classified?

a. Mobile Robots

b. Perception Systems

c. Knowledge Robots

d. Industrial Robots

Answer: (d) Industrial Robots

18. In a servomechanism, the response is 1+0.2e-60t-1.2e-10t when we subject it to a unit step input. Here, what would be the damping ratio?

a. 1.74

b. 1.59

c. 1.43

d. 1.21