An open-loop control system is characterized by which of the following?

• A. It relies on feedback to adjust control action
• B. It uses sensors to measure output
• C. It does not depend on feedback to control position
• D. It dynamically corrects errors

Answer: (C)

Open-loop control relies on a predetermined input to drive the plant without using output measurements to adjust the action. It does not use a feedback path from the output to the controller, so the control action isn’t changed in response to errors between desired and actual position. As a result, disturbances or modeling mistakes won’t be corrected automatically.

That’s why the best description is that it does not depend on feedback to control position. The other statements describe closed-loop behavior—adjusting with feedback, using sensors to measure output, and dynamically correcting errors—which are not characteristics of open-loop systems. A good way to see it is to think of a simple timer-operated device (like a toaster) that runs for a fixed period regardless of the toast’s actual color: no feedback, fixed action.