MCQOPTIONS
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MCQOPTIONS
This section includes 21 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. |
For a lead compensator having a transfer function\({G_c}\left( s \right) = \left( {\frac{{s + {z_c}}}{{s + {p_c}}}} \right) = \frac{{\left( {s + \frac{1}{\tau }} \right)}}{{\left( {s + \frac{1}{{\alpha \tau }}} \right)}}\)1. \(\alpha = \frac{{{z_c}}}{{{p_c}}} < 1\)2. \(\alpha = \frac{{{z_c}}}{{{p_c}}} > 1\)3. τ > 04. τ < 0Which of the above are correct? |
| A. | 1 and 4 |
| B. | 1 and 3 |
| C. | 2 and 4 |
| D. | 2 and 3 |
| Answer» C. 2 and 4 | |
| 2. |
In a PID controller,the values of proportional, integral and derivative are dependent on |
| A. | future, past and present errors respectively |
| B. | present, past and future errors respectively |
| C. | past, present and future errors respectively |
| D. | present, future and past errors respectively |
| Answer» C. past, present and future errors respectively | |
| 3. |
A regulator that contains four phase lags at t1, t2 = 0.1 sec, t3, t4 = 0.01 sec, is stable if its steady state gain is __________ |
| A. | 10 dB |
| B. | 30 dB |
| C. | 20 dB |
| D. | none of these |
| Answer» D. none of these | |
| 4. |
Consider the following statements:1. Lead compensation decreases the bandwidth of the system.2. Lag compensation increases the bandwidth of the system.Which of the above statements is/are correct? |
| A. | 1 only |
| B. | 2 only |
| C. | Both 1 and 2 |
| D. | Neither 1 nor 2 |
| Answer» E. | |
| 5. |
Lag-lead compensator possesses: |
| A. | One pole and two zeros |
| B. | Two poles and two zeros |
| C. | Two pols and one zero |
| D. | One pole and one zero |
| Answer» C. Two pols and one zero | |
| 6. |
A lead compensator:1. Speeds up the transient response.2. Increases the margin of stability of a system.3. Helps to increase the system error constant though to a limited extent.Which of the above statements are correct? |
| A. | 1 and 2 only |
| B. | 1 and 3 only |
| C. | 2 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 7. |
Consider the following statements regarding a PID controller :1. The error is multiplied by a negative (for reverse action) proportional constant P, and added to the current output2. The error is integrated (averaged) over a period of time, and then divided by a constant I, and added to the current control output3. The rate of change of the error is calculated with respect to time, multiplied by another constant D, and added to the outputWhich of the above statements are correct ? |
| A. | 1, 2 and 3 |
| B. | 1 and 3 only |
| C. | 1 and 2 only |
| D. | 2 and 3 only |
| Answer» B. 1 and 3 only | |
| 8. |
If both fast response time and good steady-state accuracy are needed ______ compensators are used. |
| A. | Fast |
| B. | Lead |
| C. | Lag |
| D. | Lag-Lead |
| Answer» E. | |
| 9. |
Lag compensator is a _____ |
| A. | phase shifted |
| B. | Low pass filter |
| C. | High pass filter |
| D. | resistance |
| Answer» C. High pass filter | |
| 10. |
For a lead compensator, whose transfer function is given by \(k \frac{s+a}{s+b}\); a, b ≥ 0 |
| A. | a < b |
| B. | a > b |
| C. | a ≥ kb |
| D. | a =0 |
| Answer» B. a > b | |
| 11. |
Derivative controller improves the stability by: |
| A. | reducing steady state error |
| B. | reducing settling time |
| C. | reducing oscillations |
| D. | increasing peak overshoot |
| Answer» C. reducing oscillations | |
| 12. |
Consider a controller with a lead of 35° and gain of 5.65 dB at 2.8 rad/sec. Which of the following options corresponds to transfer function of the lead compensator? |
| A. | \(\frac{\left( 1+0.2s \right)}{\left( 1+0.7s \right)}\) |
| B. | \(\frac{0.5\left( 1+0.2s \right)}{\left( 1+0.7s \right)}\) |
| C. | \(\frac{\left( 1+0.69s \right)}{1+0.19s}\) |
| D. | \(\frac{0.272\left( 1+0.69s \right)}{1+0.19s}\) |
| Answer» E. | |
| 13. |
PID controller uses _________ Between input and output |
| A. | Proportional Relation |
| B. | Integral Relation |
| C. | Differential Relation |
| D. | All of these |
| Answer» E. | |
| 14. |
Consider the following circuit models.(a) Integrator(b) Proportional + Derivative(c) Proportion + Integral + DerivativeArrange the above circuit models in decreasing order of their circuit complexity :Code : |
| A. | (a), (b), (c) |
| B. | (a), (c), (b) |
| C. | (b), (a), (c) |
| D. | (c), (b), (a) |
| Answer» E. | |
| 15. |
A phase lead compensator has its transfer function, \(T/F = \frac{{1 + 0.5\;s}}{{1 + 0.05\;s}}\). The maximum phase lead and the corresponding frequency, respectively are nearly |
| A. | sin-1(0.9)and 6 r/s |
| B. | sin-1(0.82) and 4 r/s |
| C. | sin-1(0.9) and 4 r/s |
| D. | sin-1(0.82) and 6 r/s |
| Answer» E. | |
| 16. |
A Lag network for compensation normally consists of |
| A. | R, L and C elements |
| B. | R and L elements |
| C. | R and C elements |
| D. | R only |
| Answer» D. R only | |
| 17. |
If stability error for step input and speed of response be the criteria for design, what controlled would you recommend |
| A. | P controller |
| B. | PD controller |
| C. | PI controller |
| D. | PID controller |
| Answer» E. | |
| 18. |
In general, a PI controller: |
| A. | Improves both the steady state part and the transient part |
| B. | Improves steady state part as well as transient part |
| C. | Affects both the steady state part and the transient part |
| D. | Improves steady state part affecting the transient part |
| Answer» E. | |
| 19. |
Mathematical representation of proportional control mode isWhere po is controller output with zero error and Kp is proportional gain constant. |
| A. | p(t) = Kpe(t) ÷ po |
| B. | p(t) = Kpe(t) + po |
| C. | p(t) = Kpe(t) - po |
| D. | p(t) = Kpe(t) × po |
| Answer» C. p(t) = Kpe(t) - po | |
| 20. |
Find the values of Kp, KI, and KD for PID controller whose characteristics equation has real roots at 10, ξ = 0.8 and ωn = 2 rad/s |
| A. | KD = 1.8, KP = 8, KI = 10 |
| B. | KD = 1.8, KP = 4, KI = 5 |
| C. | KD = 3.6, KP = 8, KI = 20 |
| D. | KD = 1.8, KP = 8, KI = 20 |
| Answer» B. KD = 1.8, KP = 4, KI = 5 | |
| 21. |
An ON-OFF controller is |
| A. | P controller |
| B. | Integral (I) controller |
| C. | P-I controller |
| D. | PID controller |
| Answer» B. Integral (I) controller | |