Control Systems – Multiple Choice Questions (MCQs)

1. 25. What is the controllability of a system?

   • A. Ability to move the system to any desired state
   • B. Ability to observe the system's internal states
   • C. Ability to stabilize the system
   • D. Ability to track input signals

2. 26. Observability of a system refers to:

   • A. Ability to observe the system's internal states from its outputs
   • B. Ability to control the system from its inputs
   • C. Ability to stabilize the system
   • D. Ability to measure system parameters

3. 27. The natural frequency of a second-order system is denoted by:

   • A. ζωn
   • B. ωn
   • C. ωd
   • D. τ

4. 28. Damping ratio (ζ) of a system determines the:

   • A. Speed of response
   • B. Oscillatory nature of response
   • C. Steady-state error
   • D. Bandwidth

5. 29. The bandwidth of a control system is a measure of its:

   • A. Speed of response
   • B. Stability
   • C. Accuracy
   • D. Sensitivity

6. 30. Nichols chart is a plot of:

   • A. Magnitude vs. phase
   • B. Log magnitude vs. phase
   • C. Gain vs. frequency
   • D. Phase vs. frequency

7. 31. The value of gain K for which the roots of the characteristic equation lie on the imaginary axis represents:

   • A. Critically damped response
   • B. Undamped response
   • C. Overdamped response
   • D. Underdamped response

8. 32. The concept of "time constant" is primarily associated with:

   • A. First-order systems
   • B. Second-order systems
   • C. Zero-order systems
   • D. Higher-order systems

9. 33. What is the effect of increasing the integral gain (Ki) in a PID controller?

   • A. Increases overshoot
   • B. Decreases steady-state error
   • C. Increases rise time
   • D. Decreases damping

10. 34. The maximum overshoot of a second-order system depends on the:

    • A. Natural frequency
    • B. Damping ratio
    • C. Input amplitude
    • D. Type of input

11. 35. Which of the following describes a stable system?

    • A. Poles on the right half of s-plane
    • B. Poles on the left half of s-plane
    • C. Poles on the imaginary axis
    • D. Zeros on the right half of s-plane

12. 36. A position control system is a type of:

    • A. Regulator
    • B. Servomechanism
    • C. Process control system
    • D. Sequence control system