Which statement best describes closed-loop control?

• A. Uses feedback to regulate speed or torque
• B. Does not use feedback
• C. Controls only voltage
• D. Is always faster

Answer: (A)

Closed-loop control relies on feedback from the actual output to keep the system on target. A sensor measures something like motor speed or torque, the controller compares that measurement to the desired value, and the difference (error) is used to adjust the input, such as voltage or current, to reduce the error. This feedback lets the system compensate for disturbances like changes in load or friction, maintaining the set speed or torque even when conditions change. That’s why using feedback to regulate speed or torque best describes closed-loop control.

The other ideas don’t fit as well because open-loop control uses no feedback, so it can’t automatically correct for disturbances. Limiting control to only voltage misses the broader concept of regulating output via feedback, and claiming it’s always faster ignores the fact that feedback introduces latency and is about accuracy and stability, not merely speed.