1. The term “PID” in a control system stands for:
(A) Power, Integration, Derivation
(B) Proportional, Integral, Derivative
(C) Phase, Inverse, Direct
(D) Parallel, Inductive, Differential
2. The proportional controller primarily affects the system’s:
(A) Steady-state error
(B) Damping and speed of response
(C) Oscillation frequency
(D) Time constant only
3. The integral control action helps in reducing:
(A) Overshoot
(B) Steady-state error
(C) Rise time
(D) Damping ratio
4. The derivative control action improves:
(A) Speed of response
(B) Steady-state error
(C) Stability and damping
(D) Accuracy
5. A proportional controller alone cannot eliminate:
(A) Oscillations
(B) Steady-state error
(C) Phase lag
(D) Transient response
6. The integral term in a PID controller introduces a:
(A) Zero
(B) Pole at origin
(C) Lead compensator
(D) Phase advance
7. The derivative term in a PID controller introduces a:
(A) Pole at origin
(B) Zero
(C) Integrator
(D) Lag compensator
8. A PD controller improves the system’s:
(A) Steady-state accuracy
(B) Transient response
(C) Time constant
(D) Gain margin
9. A PI controller improves:
(A) Speed of response
(B) Steady-state error
(C) Overshoot
(D) Damping ratio
10. A PID controller combines the advantages of:
(A) Lead and lag compensators
(B) P, I, and D controllers
(C) Series and parallel controllers
(D) Root locus and Bode design
11. Increasing the proportional gain generally:
(A) Increases overshoot
(B) Decreases overshoot
(C) Decreases rise time
(D) Makes the system unstable
12. Adding an integral term to a proportional controller:
(A) Eliminates steady-state error
(B) Reduces overshoot
(C) Improves phase margin
(D) Increases damping
13. Adding a derivative term to a proportional controller:
(A) Increases steady-state error
(B) Improves damping and reduces overshoot
(C) Slows down the system
(D) Causes instability
14. The main disadvantage of derivative control is that it:
(A) Increases steady-state error
(B) Amplifies noise
(C) Reduces system speed
(D) Causes oscillation
15. In a PID controller, the tuning process involves adjusting:
(A) Voltage and current
(B) Gains of P, I, and D terms
(C) Input and output frequencies
(D) Poles and zeros manually
16. A lag compensator improves:
(A) Transient response
(B) Steady-state accuracy
(C) Speed of response
(D) Damping ratio
17. A lead compensator improves:
(A) Steady-state error
(B) Transient response
(C) Phase lag
(D) Time constant
18. A lag–lead compensator is used to:
(A) Only reduce overshoot
(B) Only improve steady-state error
(C) Improve both transient and steady-state performance
(D) Only increase bandwidth
19. A lag compensator adds:
(A) A pole closer to the origin than its zero
(B) A zero closer to the origin than its pole
(C) A pole and zero at the same location
(D) Two zeros in the right-half-plane
20. A lead compensator adds:
(A) A pole closer to the origin than its zero
(B) A zero closer to the origin than its pole
(C) Two poles and no zeros
(D) A double pole at the origin
21. Compensation in control systems is primarily used to:
(A) Improve frequency response
(B) Enhance stability and performance
(C) Reduce gain
(D) Decrease phase shift
22. The process of adjusting controller parameters to achieve desired performance is called:
(A) Feedback
(B) Compensation
(C) Tuning
(D) Modulation
23. The Ziegler–Nichols method is commonly used for:
(A) Controller tuning
(B) Frequency response analysis
(C) Stability testing
(D) System modeling
24. A lead compensator adds:
(A) Positive phase to the system
(B) Negative phase to the system
(C) Zero phase to the system
(D) Only gain
25. A lag compensator adds:
(A) Positive phase to the system
(B) Negative phase to the system
(C) Zero phase to the system
(D) Phase lead and lag together
26. A lag–lead compensator is equivalent to:
(A) A cascade of lag and lead compensators
(B) A PID controller
(C) A proportional controller
(D) An integral controller
27. A lead compensator improves which of the following?
(A) Gain margin
(B) Phase margin
(C) Both gain and phase margin
(D) None
28. Which compensator improves steady-state accuracy but reduces speed of response?
(A) Lead
(B) Lag
(C) PID
(D) PD
29. A lag compensator is generally used when the system has:
(A) High steady-state error
(B) Poor transient response
(C) High damping ratio
(D) Large bandwidth
30. A lead compensator is generally used when the system has:
(A) Poor steady-state error
(B) Poor transient response or low phase margin
(C) High damping ratio
(D) High overshoot