Process Dynamics and Tuning — MCQs – EE

1. The term process dynamics refers to:
(A) Static behavior of a system
(B) Time-dependent behavior of a process
(C) Steady-state operation only
(D) Electrical characteristics of the process

2. The time constant of a process is a measure of:
(A) Process gain
(B) Speed of response
(C) Steady-state error
(D) Overshoot

3. A first-order process has:
(A) One energy storage element
(B) Two poles
(C) A nonlinear response
(D) A dead-time behavior

4. The dead time or time delay in a process represents:
(A) Instantaneous response
(B) Time taken before the output starts to respond
(C) The time constant
(D) System gain

5. The process gain represents:
(A) The change in output per unit change in input
(B) The delay in response
(C) The system damping ratio
(D) The feedback sensitivity

6. The steady-state gain of a process is:
(A) The ratio of steady-state output change to steady-state input change
(B) The instantaneous rate of change
(C) Always zero
(D) Dependent only on time delay

7. A first-order plus dead-time (FOPDT) model is commonly used to:
(A) Represent dynamic behavior of industrial processes
(B) Eliminate process lag
(C) Calculate steady-state gain only
(D) Model noise

8. Process lag is caused by:
(A) Energy storage in the system
(B) High-frequency noise
(C) Poor control tuning
(D) Signal distortion

9. Process tuning is the adjustment of:
(A) Controller parameters to achieve desired performance
(B) Mechanical alignment of instruments
(C) Valve body size
(D) Signal scaling

10. The Ziegler–Nichols method is widely used for:
(A) Controller tuning
(B) Measuring process variables
(C) Linearization
(D) Frequency analysis

11. In open-loop tuning, the process is:
(A) Tested without feedback control
(B) Controlled by feedback
(C) Operating under closed-loop feedback
(D) Disconnected from sensors

12. In closed-loop tuning, the process is:
(A) Tested under feedback control
(B) Disconnected from controller
(C) Isolated from disturbances
(D) Linearized manually

13. The ultimate gain (Ku) is defined as:
(A) The gain at which the system output oscillates continuously
(B) The gain that minimizes error
(C) The smallest possible gain
(D) The steady-state gain

14. The ultimate period (Pu) is:
(A) The period of sustained oscillations at ultimate gain
(B) The time constant of the process
(C) The dead time of the process
(D) The response delay

15. The Ziegler–Nichols tuning provides:
(A) Empirical settings for P, I, and D controllers
(B) Exact theoretical values for control parameters
(C) Instantaneous tuning
(D) Dead-time compensation

16. Increasing the proportional gain (Kp) generally:
(A) Reduces steady-state error but increases oscillations
(B) Increases steady-state error
(C) Decreases overshoot
(D) Reduces system speed

17. Increasing the integral gain (Ki) tends to:
(A) Eliminate steady-state error
(B) Increase steady-state error
(C) Slow the system response
(D) Reduce oscillations

18. Increasing the derivative gain (Kd):
(A) Improves damping and reduces overshoot
(B) Slows response
(C) Increases steady-state error
(D) Causes instability

19. Fine-tuning of a controller involves:
(A) Adjusting small changes to improve system response
(B) Redesigning the process
(C) Changing sensor location
(D) Modifying actuator type

20. Quarter-amplitude damping refers to:
(A) Successive oscillations reducing to one-fourth amplitude
(B) Sustained oscillations
(C) Critically damped response
(D) Instability

21. Overdamped response means:
(A) Slow return to steady state without oscillations
(B) Fast response with overshoot
(C) Continuous oscillations
(D) No response

22. Underdamped response means:
(A) Response oscillates before settling
(B) Very slow response
(C) No overshoot
(D) Constant error

23. A critically damped response achieves:
(A) Fastest response without overshoot
(B) Maximum overshoot
(C) Continuous oscillation
(D) No damping

24. The setpoint in a control system is:
(A) The desired value of the process variable
(B) The measured output
(C) The disturbance input
(D) The feedback signal

25. The process variable (PV) represents:
(A) The measured output of the process
(B) The desired setpoint
(C) The manipulated variable
(D) The disturbance

26. The manipulated variable (MV) is:
(A) The input adjusted by the controller
(B) The process disturbance
(C) The sensor signal
(D) The error signal

27. The error signal in a control system is the:
(A) Difference between setpoint and process variable
(B) Output of the actuator
(C) Process gain
(D) Feedback signal

28. The time constant of a slow process is generally:
(A) Large
(B) Small
(C) Zero
(D) Negative

29. Dead-time compensation is achieved using:
(A) Smith Predictor
(B) Ziegler–Nichols tuning
(C) PI controller
(D) Feedforward control only

30. A self-regulating process is one that:
(A) Returns to steady-state without external control
(B) Needs manual reset
(C) Always oscillates
(D) Is unstable

31. A non-self-regulating process is one that:
(A) Does not reach steady-state without control
(B) Automatically stabilizes
(C) Has zero gain
(D) Is purely static

32. The process reaction curve method is used to determine:
(A) Process gain, time constant, and dead time
(B) Controller output
(C) Setpoint value
(D) Steady-state error

33. Tuning constants are adjusted to achieve:
(A) Desired transient and steady-state performance
(B) Minimum process gain
(C) Constant frequency
(D) Linear signal behavior

34. Aggressive tuning generally results in:
(A) Faster response but higher overshoot
(B) Slower response and more stability
(C) Reduced gain
(D) No oscillations

35. Conservative tuning results in:
(A) Slower but more stable response
(B) Faster and less stable response
(C) No steady-state
(D) High-frequency oscillations