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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) | |