Explore topic-wise MCQs in Control Systems.

This section includes 20 Mcqs, each offering curated multiple-choice questions to sharpen your Control Systems knowledge and support exam preparation. Choose a topic below to get started.

1.

Statement 1: In constant M circles, as M increases from 1 to 8 radius of circle increases from 0 to 8 and Centre shifts from (-1,0) to (-8,0)Statement 2: The circle intersects real axis at point (-1/2, 0)

A. Statement 1 is TRUE, 2 is FALSE
B. Statement 1 is FALSE, 2 is TRUE
C. Statement 1 & 2 TRUE
D. Statement 1 & 2 FALSE
Answer» E.
2.

The gain margin for the system with open loop transfer functionG(s) H(s) = G(s) =2(1+s) / s2 is

A. 8
B. 0
C. 1
D. -8
Answer» C. 1
3.

The gain margin (in dB) of a system having the loop transfer functionG(s) H(s) = 2 / s(s+1) is

A. 0
B. 3
C. 6
D. 8
Answer» E.
4.

For the transfer functionG(s) H(s) = 1 / s(s+1) (s+0.5), the phase cross-over frequency is

A. 0.5 rad/sec
B. 0.707 rad/sec
C. 1.732 rad/sec
D. 2 rad/sec
Answer» C. 1.732 rad/sec
5.

The corner frequencies are

A. 0 and 1
B. 0 and 2
C. 0 and 1
D. 1 and 2
Answer» E.
6.

The polar plot of the open loop transfer function of a feedback control system intersects the real axis at -2. The gain margin of the system is

A. -5dB
B. 0dB
C. -6dB
D. 40dB
Answer» D. 40dB
7.

If a system has an open loop transfer function1-s / 1+s, then the gain of the system at frequency of 1 rad/s will be

A. 1
B. 1/2
C. Zero
D. -1
Answer» E.
8.

Consider the following statements:The gain margin and phase margin of an unstable system may respectively be1. Positive, positive2. Positive, negative3. Negative, positive4. Negative, negativeOf these statements

A. 1 and 4 are correct
B. 1 and 2 are correct
C. 1, 2 and 3 are correct
D. 2,3 and 4 are correctView Answer
Answer» E.
9.

The unit circle of the Nyquist plot transforms into 0dB line of the amplitude plot of the Bode diagram at

A. 0 frequency
B. Low frequency
C. High frequency
D. Any frequency
Answer» E.
10.

The open loop transfer function of a system is G(s) H(s)= K / (1+s)(1+2s)(1+3s)The phase cross over frequency ωc is

A. V2
B. 1
C. Zero
D. V3
Answer» C. Zero
11.

Consider the following statements:1. The effect of feedback is to reduce the system error2. Feedback increases the gain of the system in one frequency range but decreases in another3. Feedback can cause a system that is originally stable to become unstableWhich of these statements are correct.

A. 1,2 and 3
B. 1 and 2
C. 2 and 3
D. 1 and 3
Answer» D. 1 and 3
12.

THE_POLAR_PLOT_OF_THE_OPEN_LOOP_TRANSFER_FUNCTION_OF_A_FEEDBACK_CONTROL_SYSTEM_INTERSECTS_THE_REAL_AXIS_AT_-2._THE_GAIN_MARGIN_OF_THE_SYSTEM_IS?$

A. -5dB
B. 0dB
C. -6dB
D. 40dB
Answer» E.
13.

For the transfer function$

A. H(s) = 1 / s(s+1) (s+0.5), the phase cross-over frequency is
B. 0.5 rad/sec
C. 0.707 rad/sec
D. 1.732 rad/sec
Answer» E.
14.

The corner frequencies are$

A. 0 and 1
B. 0 and 2
C. 0 and 1
D. 1 and 2
Answer» C. 0 and 1
15.

The gain margin for the system with open loop transfer function

A. H(s) = G(s) =2(1+s) / s2 is
B. 8
C. 0
D. 1
Answer» E.
16.

If a system has an open loop transfer functio?

A.
B. 1
C. 1/2
Answer» D.
17.

If the gain of the open-loop system is doubled, the gain margin

A. Is not affected
B. Gets doubled
C. Becomes half
D. Becomes one-fourth
Answer» B. Gets doubled
18.

The open loop transfer function of a system is G(s) H(s)= K / (1+s)(1+2s)(1+3s)

A.
B. V2
C. 1
Answer» C. 1
19.

The polar plot of a transfer function passes through the critical point (-1,0). Gain margin is

A. Zero
B. -1dB
C. 1dB
D. Infinity
Answer» B. -1dB
20.

The constant M circle for M=1 is the

A. straight line x=-1/2
B. critical point (-1j0)
C. circle with r= 0.33
D. circle with r=0.67
Answer» B. critical point (-1j0)