Which statement about closed-loop control is true regarding disturbances?

• A. It is the simplest form of control
• B. It does not use sensors
• C. It cannot handle disturbances
• D. It is more robust to disturbances due to feedback

Answer: (D)

Feedback in closed-loop control relies on sensing the actual output, comparing it to the desired value, and adjusting the actuator to correct any deviation. When disturbances push the system away from its target, the sensor detects the change, and the controller applies a corrective action to bring the output back toward the setpoint. This ongoing adjustment makes the system more robust to disturbances because it actively counteracts their effect rather than leaving the output to drift. Statements that claim closed-loop control is the simplest form, that it doesn’t use sensors, or that it cannot handle disturbances aren’t accurate. Closed-loop control uses sensors and feedback, and its main advantage is its ability to reject disturbances through those continuous corrections.