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.

151.

A control system whose step responses is 0.5 (1+ e

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;">(s + 1) (s + 2)</td></tr></table>
B. <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;">(s + 1) </td></tr></table>
C. <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;">s(s + 2) </td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> 0 5s</center></td></tr><tr><td style="text-align: center;">(s + 1) (s + 2)</td></tr></table>
Answer» B. <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;">(s + 1) </td></tr></table>
Discussion
152.

A certain linear time invariant system has the state and the output equations given below

A. 1
B. 1
C. 0
D. None of these
Answer» D. None of these
Discussion
153.

In the feedback system shown in the given figure, the noise component of output is given by (assume high loop gain at frequencies of interest)

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>-N(s)</center></td></tr><tr><td style="text-align: center;">H<sub>1(s)</sub></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>N(s)</center></td></tr><tr><td style="text-align: center;">H<sub>1(s)</sub></td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>N(s)</center></td></tr><tr><td style="text-align: center;">H<sub>1</sub>(s)H<sub>2</sub>(s)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>-N(s)</center></td></tr><tr><td style="text-align: center;">H<sub>1</sub>(s)H<sub>2</sub>(s)</td></tr></table>
Answer» C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>N(s)</center></td></tr><tr><td style="text-align: center;">H<sub>1</sub>(s)H<sub>2</sub>(s)</td></tr></table>
Discussion
154.

Given G(s) = 1 - Iss(s + 2)

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» B. unstable
Discussion
155.

The system shown in the given figure has a unit step input. In order to make the steady state error 0.1, the value of K required is

A. 0.1
B. 0.9
C. 1.0
D. 9.0
Answer» E.
Discussion
156.

The second order system defined by

A. 1.2 sec
B. 1.6 sec
C. 2 sec
D. 0.4 sec
Answer» C. 2 sec
Discussion
157.

The asymptotes and the break point coincide at s = 2. The transfer function can be

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 2)</center></td></tr><tr><td style="text-align: center;">(s + 1)(s + 2)</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 2)</center></td></tr><tr><td style="text-align: center;">(s + 1)(s + 3)</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;">(s + 1)(s + 2)(s + 3)</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;">(s + 2)<sup>3</sup></td></tr></table>
Answer» E.
Discussion
158.

Consider the following statements with reference to phase lead compensator.

A. 2 and 3 are correct
B. 1 and 2 are correct
C. 1 and 3 are correct
D. 1, 2 and 3 are correct
Answer» C. 1 and 3 are correct
Discussion
159.

The open-loop transfer function with unity feedback are given below for different systems

A. 1
B. 2
C. 3
D. 4
Answer» D. 4
Discussion
160.

Consider the following statements with reference to the block diagram of a control system given in the figure

A. 1, 2 and 3 are correct
B. 1 and 2 are correct
C. 2 and 3 are correct
D. 1 and 3 are correct
Answer» D. 1 and 3 are correct
Discussion
161.

The unit impulse response of a system is given by C (t) = 0.5 e

A. 1/(s + 2)
B. 1/(1 + 2s)
C. 2/(1 + 2s)
D. 2/(s + 2)
Answer» C. 2/(1 + 2s)
Discussion
162.

The principles of homogeneity and superposition are applied to

A. Iinear time variant systems
B. non-Iinear time variant systems
C. linear time invariant systems
D. non-Iinear time invariant systems
Answer» D. non-Iinear time invariant systems
Discussion
163.

Consider the following statement regarding time-domain analysis of a control system

A. 1 and 2 are correct
B. 1 and 3 are correct
C. 2 and 3 are correct
D. 1, 2 and 3 are correct
Answer» C. 2 and 3 are correct
Discussion
164.

The solution set for the variables X, Y in the signal flow graph shown in the figure below is

A. X = Y = 0
B. X = 1/2, Y = 2
C. X = 2, Y = 1/2
D. X = Y = 1/2
Answer» B. X = 1/2, Y = 2
Discussion
165.

The system with transfer function

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» C. marginally stable
Discussion
166.

By a suitable choice of the scalar parameter K, the system shown in the figure below, can be made to oscillate continuously at a frequency of

A. 1 rad/s
B. 2 rad/s
C. 4 rad/s
D. 8 rad/s
Answer» D. 8 rad/s
Discussion
167.

Consider a system shown in the given figure. If the system is disturbed so that C (0) = 1, then C (t) for a unit step input will be

A. 1 + t
B. 1 t
C. 1 + 2t
D. 1 2t
Answer» D. 1 2t
Discussion
168.

As compared to a closed loop system an open loop system is

A. more stable as well as more accurate
B. less stable as well as less accurate
C. more stable but less accurate
D. less stable but more accurate.
Answer» D. less stable but more accurate.
Discussion
169.

The open-loop transfer function of a unity negative feed back control system is given by

A. stable and stable
B. unstable and stable
C. stable and unstable
D. unstable and unstable
Answer» C. stable and unstable
Discussion
170.

A network has a pole at s = 1 and a zero at s = 2. If this network is excited by sinusoidal input, the output

A. leads the input
B. lags the input
C. is in phase with input
D. decays exponentially to zero
Answer» C. is in phase with input
Discussion
171.

The transfer function G (s) is

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» B. unstable
Discussion
172.

A lead compensating network

A. All
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer» B. (i) and (iv)
Discussion
173.

In the signal flow graph of figure shown below y/x equal to

A. 3
B. 5/2
C. 2
D. None of these
Answer» D. None of these
Discussion
174.

Bode plots of an open-loop transfer function of a control system are shown in the given figure. The gain margin of the system is

A. K
B. K
C. 1/K
D. 1/K
Answer» B. K
Discussion
175.

If the characteristic equation of a system is

A. 0 < K < 784
B. 1 < K < 64
C. 10 > K > 660
D. 4 < K < 784
Answer» B. 1 < K < 64
Discussion
176.

If the system has multiple poles on the Y-axis the system is

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» D. conditionally stable
Discussion
177.

The polar plot of a closed-loop system with a transfer function G/1 + GH is drawn for

A. G
B. 1 + GH
C. GH
D. G/1 + GH
Answer» D. G/1 + GH
Discussion
178.

The Nyquist plot of a open loop transfer function G (j ) H(j ) of a system encloses the ( 1, j0) point, the gain margin of the system is

A. less than zero
B. zero
C. greater than zero
D. infinity
Answer» B. zero
Discussion
179.

The transfer function of a system is given by

A. Fig: - A
B. Fig: - B
C. Fig: - C
D. Fig: - D
Answer» D. Fig: - D
Discussion
180.

The signal flow diagram of a system is shown in the given figure. The number of forward paths and the number of pairs of non-touching loops are respectively

A. 3, 1
B. 3, 2
C. 4, 2
D. 2, 4
Answer» B. 3, 2
Discussion
181.

The Nyquist plot for a control system is shown in figure. The Bode plot for the same system will be as in

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» E.
Discussion
182.

The open-loop transfer function of a system is given by

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» B. Fig:- B
Discussion
183.

The Nyquist locus of a transfer function

A. <table><tr><td rowspan="2">G(s) H(s) = </td><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(1 + sT<sub>1</sub>)</td></tr></table>
B. <table><tr><td rowspan="2">G(s) H(s) = </td><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 + sT<sub>1</sub>)(1 + sT<sub>2</sub>)</td></tr></table>
C. <table><tr><td rowspan="2">G(s) H(s) = </td><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(1 + sT<sub>1</sub>)(1 + sT<sub>2</sub>)</td></tr></table>
D. <table><tr><td rowspan="2">G(s) H(s) = </td><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(1 + sT<sub>1</sub>)(1 + sT<sub>2</sub>)(1 + sT<sub>3</sub>)</td></tr></table>
Answer» C. <table><tr><td rowspan="2">G(s) H(s) = </td><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(1 + sT<sub>1</sub>)(1 + sT<sub>2</sub>)</td></tr></table>
Discussion
184.

A unity feedback system has the open-loop transfer function

A. never
B. once
C. twice
D. thrice
Answer» C. twice
Discussion
185.

A unity feedback system has an open-loop transfer function of the from

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» B. Fig:- B
Discussion
186.

The system having the Bode magnitude plot shown in figure has the transfer function

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>60 (s + 0 01)(s + 0 1)</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 0 05)<sup>2</sup></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>5(1 + 10s)</center></td></tr><tr><td style="text-align: center;">s(1 + 20s)</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>8(s + 0 05)</center></td></tr><tr><td style="text-align: center;">s(s + 0 1)(s + 1)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>5(s + 0 1)</center></td></tr><tr><td style="text-align: center;">s(s + 0 05)</td></tr></table>
Answer» E.
Discussion
187.

The characteristic equation of a closed loop system is given by s

A. 0 < K < 10
B. K > 10
C. K <
D. 0 < K 20
Answer» B. K > 10
Discussion
188.

For a second order system, damping ratio ( ) is 0 <

A. real but not equal
B. real and equal
C. complex conjugates
D. imaginary
Answer» D. imaginary
Discussion
189.

The step error coefficient of a system G(s) = 1/(s + 6) (s + 1) with unity feedback is

A. 1/6
B.
C. 0
D. 1
Answer» B.
Discussion
190.

A process with open-loop model

A. the integral mode improves transient performance.
B. the integral mode improves steady-state performance
C. the derivative mode improves transient performance
D. the derivative mode improves steady-state performance.
E. B and C both
Answer» F.
Discussion
191.

The first two rows of Routh s tabulation of a fourth-order system are

A. 0
B. 2
C. 3
D. 4
Answer» C. 3
Discussion
192.

The pole-zero configuration of a phase-lead compensator is given by

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» B. Fig:- B
Discussion
193.

The root locus of a unity feedback system is shown in the above figure. The open-loop transfer function is given by

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;"> s (s + 1) (s + 2)</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 1)</center></td></tr><tr><td style="text-align: center;">s (s + 2)</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K(s + 2)</center></td></tr><tr><td style="text-align: center;">s (s + 1)</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>Ks</center></td></tr><tr><td style="text-align: center;">(s + 1)(s + 2)</td></tr></table>
Answer» D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>Ks</center></td></tr><tr><td style="text-align: center;">(s + 1)(s + 2)</td></tr></table>
Discussion
194.

G

A. minimum phase, all pass and non-minimum phase functions
B. minimum phase, non-minimum phase and all pass functions
C. all pass, minimum phase and non-minimum phase functions
D. all pass, non-minimum phase and minimum phase functions.
Answer» C. all pass, minimum phase and non-minimum phase functions
Discussion
195.

Which one of the following statements are true of a type 1 system having unit gain in the forward path and a unity feedback?

A. 1, 2 and 3
B. 1 and 2
C. 2 and 3
D. 1 and 3
Answer» C. 2 and 3
Discussion
196.

System has phase margin PM = 45 . The damping ratio is

A. 1
B. 0.5
C. 0
D. 0.42
Answer» E.
Discussion
197.

The frequency at which the Nyquist diagram cuts ( 1, 0) circle is known as

A. gain crossover frequency
B. phase crossover frequency
C. damping frequency
D. natural frequency
Answer» B. phase crossover frequency
Discussion
198.

The frequency at which the Nyquist diagram crosses the negative real axis is known as

A. gain crossover frequency
B. phase crossover frequency
C. damping frequency
D. natural frequency
Answer» C. damping frequency
Discussion
199.

Given that the transfer function G (s) is

A. 2 and 3
B. 3 and 2
C. 3 and 3
D. 2 and 2
Answer» B. 3 and 2
Discussion
200.

A system has the transfer function (1 s)/ (1 + s). It is a

A. non-minimum phase system
B. minimum phase system
C.
D. low-pass system
E. second order system
Answer» B. minimum phase system
Discussion