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.

201.

G(s) =
1 + s
s(1 + 0 5s)
A. 0 and 1
B. 0 and 2
C. 0 and 1
D. 1 and 2
Answer» E.
Discussion
202.

The forward transfer function of a system is 10/1 + s. The steady state error to unit step input when operated as a unity feedback system is

A. 10
B. 0
C. 1/11
D.
Answer» D.
Discussion
203.

For a standard feedback control loop, the sensitivity of the closed-loop transfer function T to forward path gain G and feedback path gain H are

A. A
B. B
C. C
D. D
Answer» E.
Discussion
204.

For the signal flow graph shown below, the transmittance between X2 and X1 is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rsu</td><td rowspan="2"> + </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">efh</td></tr><tr><td style="text-align: center;">1 - st</td><td style="text-align: center;">1 - fg</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rsu</td><td rowspan="2"> + </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">efh</td></tr><tr><td style="text-align: center;">1 - fg</td><td style="text-align: center;">1 - st</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">efh</td><td rowspan="2"> + </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rsu</td></tr><tr><td style="text-align: center;">1 - ru</td><td style="text-align: center;">1 - eh</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rst</td><td rowspan="2"> + </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rsu</td></tr><tr><td style="text-align: center;">1 - eh</td><td style="text-align: center;">1 - st</td></tr></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">rsu</td><td rowspan="2"> + </td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">efh</td></tr><tr><td style="text-align: center;">1 - fg</td><td style="text-align: center;">1 - st</td></tr></table>
Discussion
205.

For the network in given figure, V

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>Cs</center></td></tr><tr><td style="text-align: center;">RCs<sup>2</sup> + RCs + 1</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>C</center></td></tr><tr><td style="text-align: center;">RCs<sup>2</sup> + RCs + 1</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>Cs</center></td></tr><tr><td style="text-align: center;">RCs<sup>2</sup> + LCs + 1</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>C</center></td></tr><tr><td style="text-align: center;">RCs<sup>2</sup> + LCs + 1</td></tr></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>C</center></td></tr><tr><td style="text-align: center;">RCs<sup>2</sup> + RCs + 1</td></tr></table>
Discussion
206.

For the system shown in figure, with a damping ratio for 0.7 and an undamped natural frequency n of 4 rad/sec, the value of k and a are

A. K = 4, a = 0.35
B. K = 8, a = 0.455
C. K = 16, a = 0.225
D. K = 64, a = 0.9
Answer» D. K = 64, a = 0.9
Discussion
207.

The transfer function C (s)/ R (s) of the system, whose block diagram is given below is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>H<sub>1</sub>+G<sub>2</sub>H<sub>2</sub> - G<sub>1</sub>G<sub>2</sub>H<sub>1</sub>H<sub>2</sub></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>H<sub>1</sub>+G<sub>2</sub>H<sub>2</sub> + G<sub>1</sub>G<sub>2</sub>H<sub>1</sub>H<sub>2</sub></td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>H<sub>1</sub>+G<sub>2</sub>H<sub>2</sub></td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>(1 + G<sub>2</sub>H<sub>2</sub>) + G<sub>2</sub>(1 + G<sub>1</sub>H<sub>1</sub>)</center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>H<sub>1</sub>+G<sub>2</sub>H<sub>2</sub> + G<sub>1</sub>G<sub>2</sub>H<sub>1</sub>H<sub>2</sub></td></tr></table>
E.
Answer» C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>H<sub>1</sub>+G<sub>2</sub>H<sub>2</sub></td></tr></table>
Discussion
208.

In the signal flow graph shown in the figure, the correct relationship between the various variables is

A. w = au + bx + cy du
B. w = au + bx + cy
C. w = au + cy + bx
D. w = au + cy + bx dw
Answer» C. w = au + cy + bx
Discussion
209.

The transfer function for the given Bode plot is

A. <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<sup>2</sup>{s/5( + 1)}</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/5( + 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;">s<sup>2</sup>(s + 1){s/5( + 1)}</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>K{s/5( + 1)}</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup>(s + 1)</td></tr></table>
Answer» 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/5( + 1)}</td></tr></table>
Discussion
210.

The transfer function of a tacheometer is of the form

A. Ks
B. K/ s
C. K/ (s+1)
D. K/ [s (s+1)]
Answer» B. K/ s
Discussion
211.

Non-minimum phase transfer function is defined as the transfer function

A. which has zeros in the right-half s-plane
B. which has zeros only in the left-half s-plane
C. which has poles in the right-half s-plane
D. which has poles in the left-half s-plane
E. A and C both
Answer» F.
Discussion
212.

Signal flow graph is used to find

A. stability of the system
B. controllability of the system
C. transfer function of the system
D. poles of the system
Answer» D. poles of the system
Discussion
213.

What is the gain of the system given below?

A. 36
B. 13.25
C. 11
D. - 13.25
Answer» D. - 13.25
Discussion
214.

A system has transfer function (2 s)/(2 + s) what is it s gain at 2 rad/sec?

A. 1
B. 0
C.
D. 2/5
Answer» B. 0
Discussion
215.

A system has transfer function

A. non-minimum phase system
B. minimum phase system
C. low phase system
D. second order system
Answer» B. minimum phase system
Discussion
216.

The block diagram shown in figure (a) is to be represented as in figure (b) for what value of H(s)?

A. 5s + 1
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s + 1</center></td></tr><tr><td style="text-align: center;">s</td></tr></table>
C. 5(s + 1)
D. s(s + 5)
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s + 1</center></td></tr><tr><td style="text-align: center;">s</td></tr></table>
Discussion
217.

The type denotes the number of

A. poles of infinity
B. poles of origin
C. zeros of infinity
D. zeros of origin
Answer» C. zeros of infinity
Discussion
218.

If the closed loop transfer function s damping ratio is 0.5 what is the value of M?

A. 16
B. 22
C. 19
D. 110
Answer» D. 110
Discussion
219.

If the unit step response of a system is a unit impulse function, then the transfer function of such a system will be

A. 1
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</td></tr></table>
C.
D. s
E. <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<sup>2</sup></td></tr></table>
Answer» D. s
Discussion
220.

The Transfer function of a system is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>T</center></td></tr><tr><td style="text-align: center;">K</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;">K + T</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>T</center></td></tr><tr><td style="text-align: center;">T + K</td></tr></table>
D. K + T
Answer» D. K + T
Discussion
221.

The transmittance from X to Y in the signal flow graph shown in the figure is

A. 4/3
B. 1
C. 2/3
D. 1/3
Answer» D. 1/3
Discussion
222.

The block diagram shown in fig. (a) is to be represented as in figure (b). What is the value of H (s)?

A. 2s + 1
B. s + 1
C. 2(s + 1)
D. s(s + 1)
Answer» B. s + 1
Discussion
223.

For the feedback system shown in the given figure, the forward path does not affect the system output. When KG is

A. small
B. negative
C. one
D. very large
Answer» E.
Discussion
224.

A system with the characteristic equation s4 + 2s3 + 11s2 + 18s + 18 = 0 will have closed loop poles such that

A. all poles lie in the left half of the s-plane
B. all poles lie in the right half of the s-plane
C. two poles lie symmetrically on the imaginary axis of the s-plane
D. no pole lie on the imaginary axis of the s-plane
Answer» D. no pole lie on the imaginary axis of the s-plane
Discussion
225.

Consider the following overall T.F. for a unity feedback system

A. 1, 2, 3
B. 1, 2
C. 2, 3
D. s1, 3
Answer» E.
Discussion
226.

The condition of a stability for a unity feedback control system whose open loop transfer function is given by

A. T < 2
B. T = 2
C. T > 2
D. 0
Answer» B. T = 2
Discussion
227.

The transfer function V(s) /I(s) in the signal flow graph shown in the figure is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s<sup>2</sup></center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + s + 1</td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s<sup>2</sup> - s - 1</center></td></tr><tr><td style="text-align: center;">s</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s</center></td></tr><tr><td style="text-align: center;">s + 1/s</td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s</center></td></tr><tr><td style="text-align: center;">s<sup>2</sup> + s + 1</td></tr></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>s<sup>2</sup> - s - 1</center></td></tr><tr><td style="text-align: center;">s</td></tr></table>
Discussion
228.

If the Intermediate variable C in the signal flow graph shown in the figure has a value 10, the input A has a value

A. 20
B. 25
C. 30
D. 35
Answer» C. 30
Discussion
229.

Consider the following signal flow graph, which have the same transfer function, would include

A. 1 and 2
B. 2 and 3
C. 2 and 4
D. 1 and 4
Answer» D. 1 and 4
Discussion
230.

Consider the following statements 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
231.

In a linear system, an input of 5 sin t produces an output of 10 cos t. The output corresponding to input 10 cos t will be equal to

A. + 5 sin t
B. 5 sin t
C. + 20 sin t
D. 20 sin t
Answer» E.
Discussion
232.

Sinusoidal oscillators are

A. stable
B. unstable
C. marginally stable
D. conditionally stable
Answer» C. marginally stable
Discussion
233.

Gain cross-over frequency is defined as

A. | G (j ) H (j ) | = 1
B. | G (j ) H (j ) | = 0
C. | G (j ) H (j ) | =
D. | G (j ) H (j ) | = 1/2
Answer» B. | G (j ) H (j ) | = 0
Discussion
234.

A plot of open-loop poles/zeros of a unity feedback control system is shown in the given figure Its root-locus plot will be

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» E.
Discussion
235.

Consider the following properties attributed to state model of a system

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
236.

A unity feedback system has OLTF, G (s) = 9/s(s + 3)

A. Natural frequency = 9 rad/sec.
B. Natural frequency = 3 rad/sec.
C. Damping ratio = 1/2
D. Damping ratio = 1/6
Answer» B. Natural frequency = 3 rad/sec.
Discussion
237.

Which one of the four signals flow graphs shown in (A), (B), (C) and (D) represents the block diagram shown in given figure?Kindle Edition.

A. Fig :- A
B. Fig :- B
C. Fig :- C
D. Fig :- D
Answer» B. Fig :- B
Discussion
238.

The unit step response of a second order linear system with zero initial states is given by

A. 0.6 and 10 rad/s
B. 0.6 and 12.5 rad/s
C. 0.8 and 10 rad/s
D. 0.8 and 12.5 rad/s
Answer» B. 0.6 and 12.5 rad/s
Discussion
239.

The Laplace transformation of f (t) is

A. infinity
B. zero
C. one
D. None of these
Answer» E.
Discussion
240.

A minimum-phase function has m finite poles and n finite zeros. Its phase angle as is, where n > m

A. 0 radians
B. (m n) /2 radians
C. (m n) /2 radians
D. radians
Answer» C. (m n) /2 radians
Discussion
241.

The transfer function C/R of the block diagram given below is

A. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + H<sub>1</sub>H<sub>2</sub></td></tr></table>
B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">G<sub>1</sub>G<sub>2</sub>(H<sub>1</sub> + H<sub>2</sub>) + 1</td></tr></table>
C. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>1</sub>G<sub>2</sub>H<sub>1</sub> + H<sub>2</sub></td></tr></table>
D. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">1 + G<sub>2</sub>H<sub>1</sub> G<sub>1</sub>H<sub>2</sub></td></tr></table>
Answer» B. <table><tr><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>G<sub>1</sub>G<sub>2</sub></center></td></tr><tr><td style="text-align: center;">G<sub>1</sub>G<sub>2</sub>(H<sub>1</sub> + H<sub>2</sub>) + 1</td></tr></table>
Discussion
242.

The Laplace transform of f(t) is F(s).

A. infinity
B. zero
C. one
D. None of these
Answer» B. zero
Discussion
243.

A second order system is given as

A. gets increased
B. gets decreased
C. is unaffected
D. gets decreased and becomes stable
Answer» C. is unaffected
Discussion
244.

Which of the following figure(s) represent valid root loci in the s-plane for positive K? Assume that the system has a transfer function with real coefficients

A. Fig:- A
B. Fig:- B
C. Fig:- C
D. Fig:- D
Answer» B. Fig:- B
Discussion
245.

Signal flow graph is used to obtain the

A. stability of the system
B. transfer function of a system
C. controllability of a system
D. observability of a system
Answer» C. controllability of a system
Discussion
246.

Consider the following statements regarding a first order system with a proportional (P) controller which exhibits an offset to a unit step input.

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» C. 2 and 3 are correct
Discussion
247.

The Laplace transform of the function i(t) is

A. 4/5
B. 5/4
C. 4
D. 5
Answer» B. 5/4
Discussion
248.

The pole-zero plot given below is that of a/an

A. integrator
B. PD controller
C. PID controller
D. lag-lead compensating network
Answer» E.
Discussion
249.

The term reset control refers to

A. proportional control
B. integral control
C. derivative control
D. None of these
Answer» C. derivative control
Discussion
250.

The characteristic equation of a unity feedback control system is given by s

A. 1 and 2 are correct
B. 3 alone is correct
C. 2 alone is correct
D. 1 and 3 are correct
Answer» B. 3 alone is correct
Discussion