Correct AnswerC. Modify control signals
Quick Explanation
A controller processes the error/control information and modifies the control signal so the plant responds according to desired performance requirements. It may amplify, integrate, differentiate, shape or otherwise compensate the signal.
Detailed Explanation
Concept & Reasoning
In a feedback loop, the comparator forms error between reference and measured output. The controller applies a control law—P, PI, PD, PID, state feedback, etc.—to transform that error into a suitable actuator command. Its purpose is not merely to receive or transmit a signal; it deliberately shapes system behavior.
How to Solve It in the Exam
Controller = signal-shaping decision element.
Important Exam PointThink performance: accuracy, speed, damping, robustness.
Related Revision Path
This question sits in the revision path Control Systems → Controllers → Role of Controller .
