Explore topic-wise MCQs in Control Systems.

This section includes 283 Mcqs, each offering curated multiple-choice questions to sharpen your Control Systems knowledge and support exam preparation. Choose a topic below to get started.

101.

An integral controller is used to improve the transient response of a first order system. If G (s) = 1/1 + s and the system is operated in closed-loop with unity feedback, what is the value of T

A. 0.5
B. 2
C. 1
D. 4
Answer» D. 4
Discussion
102.

A control system is as shown in the given figure. The maximum value of gain K for which the system is stable is

A. 3
B. 3
C. 4
D. 5
Answer» E.
Discussion
103.

The open loop transfer function of a unity feedback control system is given by:

A. 1/ 2
B. 1
C. 0
D.
Answer» D.
Discussion
104.

Two identical first-order systems have been cascaded non-interactively. The unit step response of the systems will be

A. overdamped
B. underdamped
C. undamped
D. critically damped
Answer» E.
Discussion
105.

For the given Bode plot the value of K

A. 25
B. 50
C. 15.9
D. None of these
Answer» B. 50
Discussion
106.

If the closed-loop transfer function of unity negative feedback system is given by

A. an. an 1
B. an. an 2
C. an 2. an
D. Zero
Answer» D. Zero
Discussion
107.

The position and acceleration error coefficients for the open-loop transfer function

A. zero and infinity
B. infinity and zero
C. K/100 and zero
D. infinity and K/100
Answer» E.
Discussion
108.

A unity feedback control system has a forward path transfer function equal to 42 25/s(s + 6 5) The unit step response of this system starting from rest, will have its maximum value at a time equal to

A. 0 sec
B. 0.56 sec
C. 5.6 sec
D. infinity
Answer» E.
Discussion
109.

The overshoot of the system

A. 60%
B. 40%
C. 20%
D. 10%
Answer» C. 20%
Discussion
110.

For the unity feedback system shown below, the steady state, when the input is

A. 1/4
B. 0
C.
D. 1/2
Answer» B. 0
Discussion
111.

In the unity feedback system shown below, the value of derivative feedback constant a, which will increase the damping ratio of the system to 0.7 is

A. 0.152
B. 0.245
C. 0.353
D. 0.558
Answer» C. 0.353
Discussion
112.

The transfer function of a system is 10/1 + s. When operated as a unity feedback system, the steady state error to a unit step input will be

A. zero
B. 9
C. 10
D. infinity
Answer» C. 10
Discussion
113.

The value of 1 for the data given is Q. 251

A. 4 rad/sec
B. 2 rad/sec
C. 5 rad/sec
D. 1 rad/sec
Answer» C. 5 rad/sec
Discussion
114.

Consider a system shown in the given flgure with

A. K = 2, a = 1
B. K = 2, a = 0.75
C. K = 4, a = 1
D. K = 4, a = 0.75
Answer» C. K = 4, a = 1
Discussion
115.

If the open-loop transfer function of the system is

A. 4355
B. 2436
C. 9600
D. 2463
Answer» C. 9600
Discussion
116.

Consider the control system shown in the following figure and the statements given below.

A. 1 and 2 are correct
B. 2 and 4 are correct
C. 2, 3 and 4 are correct
D. 1, 2 and 3 are correct
Answer» C. 2, 3 and 4 are correct
Discussion
117.

The transfer function Eo (s)/Ei (s) of the circuit is

A. sL/R
B. 1 + sL/R
C. R + sL/R
D. s/(s + R/L)
Answer» E.
Discussion
118.

G (s) =
K
s(1 + sT)
A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» E.
Discussion
119.

The transfer function of a closed-loop system is

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» C. marginally stable
Discussion
120.

Consider the following polynomials

A. 1 and 3
B. 2 and 3
C. 1 and 2
D. 1, 2 and 3
Answer» D. 1, 2 and 3
Discussion
121.

The magnitude-frequency response of a control system is shown in the figure. The value of

A. 10 and 200
B. 20 and 200
C. 20 and 400
D. 100 and 400
Answer» D. 100 and 400
Discussion
122.

The open-loop transfer function of a unity feedback control system is: G(s) = 1/(s + 2)

A. 2, 2
B. 2, 1
C. 2, j1
D. 2, j2
Answer» D. 2, j2
Discussion
123.

Consider a closed loop system shown in figure (a) below. The root locus for it is shown in figure (b). The closed-loop transfer function for the system is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">1 + (0 5s + 1) (10s + 1)</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">(s + 2) (s + 0 1)</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">1 + K (0 5s + 1) (10s + 1)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K</center></td></tr><tr><td style="text-align: center;">K + (0 5s + 1) (10s + 1) </td></tr></table>
Answer» E.
Discussion
124.

129. For what values of a does the system shown in figure have a zero steady s`tate error (i.e. Lim t e(t)) for a step input?

A. a = 0
B. a > 0
C. a 4
D. For no value of a
Answer» B. a > 0
Discussion
125.

The overall transfer function of the system in figure is

A. G/1 GH
B. 2G/1 GH
C. GH/1 GH
D. 2G/1 H
Answer» C. GH/1 GH
Discussion
126.

Transfer function G(s) has the pole-zero as shown in the given figure. Given that the steady state gain is 2, the transfer function G(s) will be given by

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>5(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 4</td></tr></table>
C.
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
E. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">(s + 2)<sup>2</sup></td></tr></table>
Answer» D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
Discussion
127.

The state and output equation of a system are as under state equation:

A. neither state controllable nor output controllable
B. state controllable but not output controllable
C. output controllable but not state controllable
D. both state controllable and output controllable
Answer» C. output controllable but not state controllable
Discussion
128.

Obtain the transfer function for the response curve shown below

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>40</center></td></tr><tr><td style="text-align: center;">s(1 + 0 1s)</td></tr></table>
B.
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">s(1 + 0 1s)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">s(1 + 0 01s)</td></tr></table>
E. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>20</center></td></tr><tr><td style="text-align: center;">s(1 + 0 1s)</td></tr></table>
Answer» D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">s(1 + 0 01s)</td></tr></table>
Discussion
129.

The feedback control system shown in the given figure represents a

A. Type 0 system
B. Type 1 system
C. Type 2 system
D. Type 3 system
Answer» B. Type 1 system
Discussion
130.

The transfer function 0(s) 1(s) of the block diagram is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>3</sub>G<sub>4</sub></center></td></tr><tr><td style="text-align: center;">1 + H<sub>1</sub>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub> + H<sub>2</sub>G<sub>4</sub></center></td></tr><tr><td style="text-align: center;">1 + H<sub>1</sub>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub></td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub> + H<sub>2</sub>G<sub>4</sub></center></td></tr><tr><td style="text-align: center;">1 + H<sub>1</sub>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub> + H<sub>2</sub>G<sub>4</sub>H<sub>1</sub></td></tr></table>
D.
E. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub> + H<sub>2</sub>G<sub>4</sub></center></td></tr><tr><td style="text-align: center;">1 + H<sub>1</sub>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub> + H<sub>1</sub>H<sub>2</sub>G<sub>2</sub>G<sub>3</sub>G<sub>4</sub></td></tr></table>
Answer» D.
Discussion
131.

A unity feedback system has an open loop transfer function, G(s) = K/s>sup>2. The root locus plot is

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» C. Fig:- C
Discussion
132.

A unity feedback system has open-loop T.F. is G(s) = {25/ [s (s + 6)]}. The peak overshoot in the step-input response of the system is approximately equal to

A. 5%
B. 10%
C. 15%
D. 20%
Answer» C. 15%
Discussion
133.

In the network shown in the given figure. If the voltage V at the time considered is 20 V, then dV/dt at that time will be

A. 1 V/s
B. 2 V/s
C. 2 V/s
D. Zero
Answer» C. 2 V/s
Discussion
134.

The transfer function of a compensating network is of the form (1 + Ts)/ (1 + Ts). If this is a phase-lag network, the value of should be

A. exactly equal to 0
B. between 0 and 1
C. exactly equal to 1
D. greater than 1.
Answer» C. exactly equal to 1
Discussion
135.

A transfer function G (s) has the pole-zero plot as shown in the given figure. Given that the steady state is 2, the transfer function G (s) will be given by

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>5(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 4</td></tr></table>
C.
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
E. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">(s + 2)<sup>2</sup></td></tr></table>
Answer» D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10(s + 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + 4s + 5</td></tr></table>
Discussion
136.

In the signal flow graph of figure the gain C/R will be

A. 11/9
B. 22/15
C. 24/23
D. 44/23
Answer» E.
Discussion
137.

G (s) =
1 s
s(s + 2)
A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» B. unstable
Discussion
138.

The transfer function has a log-magnitude plot as shown below. Under the assumption that a minimum phase function, its transfer function is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>1</center></td></tr><tr><td style="text-align: center;">1 + s</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10</center></td></tr><tr><td style="text-align: center;">1 + s</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10</center></td></tr><tr><td style="text-align: center;">s + 10</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> <span style=" text-decoration: overline;">2</span></center></td></tr><tr><td style="text-align: center;">s + 0.1</td></tr></table>
Answer» E.
Discussion
139.

The transfer function of a closed loop system is 1/1 + sT. The input to this system is t u(t). The output would track this system, but the error would be

A. 0
B. T
C. <sup>2 <br></sup>
D. T
E. T/2
Answer» D. T
Discussion
140.

The transfer function is

A. 0 and 1
B. 1 and 2
C. 2 and 3
D. beyond 3
Answer» C. 2 and 3
Discussion
141.

The root locus plot is shown below. What is the transfer function?

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">1 + s</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">(s + 1)<sup>2</sup></td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">(s + 1)<sup>3</sup></td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>4</center></td></tr><tr><td style="text-align: center;">(s + 1)<sup>4</sup></td></tr></table>
Answer» E.
Discussion
142.

The value of 2 for the data given in Q. 251

A. 8 rad/sec
B. 16 rad/sec
C. 2 rad/sec
D. 4 rad/sec
Answer» C. 2 rad/sec
Discussion
143.

Find the value of K for the given Bode plot

A. 80
B. 40
C. 20
D. 10
Answer» B. 40
Discussion
144.

The transfer function of transportation lag is e

A. sT
B. 1 + sT
C. 1 sT
D. 1/1 + sT
Answer» D. 1/1 + sT
Discussion
145.

Consider a unit feedback control system with open-loop transfer function

A. zero
B. K
C. 1/ K
D.
Answer» B. K
Discussion
146.

The transfer function for the Bode plot given below is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10<sup>5</sup></center></td></tr><tr><td style="text-align: center;">(1+s/5)(1+s/40)(1+s/100)</td></tr></table>
B.
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10<sup>6</sup></center></td></tr><tr><td style="text-align: center;">(1+s/5)(1+s/40)<sup>2</sup>(1+s/100)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10<sup>5</sup></center></td></tr><tr><td style="text-align: center;">(1+s/5)(1+s/40)<sup>2</sup>(1+s/100)</td></tr></table>
E. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10<sup>6</sup></center></td></tr><tr><td style="text-align: center;">(1+s/5)(1+s/40)(1+s/100)<sup>2</sup></td></tr></table>
Answer» D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>10<sup>5</sup></center></td></tr><tr><td style="text-align: center;">(1+s/5)(1+s/40)<sup>2</sup>(1+s/100)</td></tr></table>
Discussion
147.

The gain factor K for the data given in Q. 251

A. 16
B. 32
C. 8
D. 64
Answer» C. 8
Discussion
148.

The value of 3 for the data given in Q. 251

A. 40 rad/sec
B. 20 rad/sec
C. 32 rad/sec
D. None of these
Answer» B. 20 rad/sec
Discussion
149.

For a unit step input, a system with forward path transfer function G(s) = 20/s

A. 20
B. 5
C. 0.2
D. zero
Answer» E.
Discussion
150.

The error response of a second order system to a step input is obtained as

A. 0.4
B. 0.5
C. 0.8
D. 1.0
Answer» D. 1.0
Discussion