Control Systems – Multiple Choice Questions (MCQs)

1. 37. The closed-loop transfer function of a unity feedback system with open-loop transfer function G(s) is:

   • A. G(s) / (1 + G(s))
   • B. G(s) / (1 - G(s))
   • C. 1 / (1 + G(s))
   • D. 1 / (1 - G(s))

2. 38. The steady-state error to a parabolic input for a type 2 system is:

   • A. Zero
   • B. Infinite
   • C. Constant
   • D. Undefined

3. 39. What is the primary advantage of state-space representation over transfer function representation?

   • A. Easier for higher-order systems
   • B. Handles multiple inputs/outputs
   • C. Provides internal state information
   • D. All of the above

4. 40. Which of the following is a drawback of using only proportional control?

   • A. Offset (steady-state error)
   • B. Slow response
   • C. Oscillations
   • D. Instability

5. 41. The term "robustness" in control systems refers to:

   • A. Ability to withstand disturbances
   • B. Insensitivity to parameter variations
   • C. Ability to track commands accurately
   • D. Speed of response

6. 42. The output of a system follows the input with a time delay and magnitude change. This indicates:

   • A. Ideal response
   • B. Proportional control
   • C. Lag
   • D. Lead

7. 43. What is the effect of phase lead compensation?

   • A. Increases bandwidth
   • B. Decreases bandwidth
   • C. Increases steady-state error
   • D. Decreases transient response

8. 44. A non-minimum phase system has zeros in the:

   • A. Left half of s-plane
   • B. Right half of s-plane
   • C. Imaginary axis
   • D. Origin

9. 45. The final value theorem is used to find the:

   • A. Initial value of a function
   • B. Steady-state value of a function
   • C. Laplace transform
   • D. Inverse Laplace transform

10. 46. The initial value theorem is used to find the:

    • A. Initial value of a function
    • B. Steady-state value of a function
    • C. Laplace transform
    • D. Inverse Laplace transform

11. 47. The sensitivity of the roots of the characteristic equation to variations in system parameters is analyzed using:

    • A. Root locus
    • B. Bode plot
    • C. Nyquist plot
    • D. Sensitivity analysis

12. 48. What is the main purpose of a sensor in a feedback control system?

    • A. To actuate the system
    • B. To compare input and output
    • C. To measure the output
    • D. To provide power