Question

A closed loop system is distinguished from open loop system by which of the following?

(a) Servomechanism

(b) Feedback

(c) Output pattern

(d) Input pattern

This question was addressed to me during an online exam.

This interesting question is from Parameter Optimization : Servomechanims in division Optimal Control Systems of Control Systems

Answer 1

The correct answer is:

(b) Feedback

Explanation:

A closed-loop system is characterized by the presence of feedback, where the system continuously monitors its output and adjusts its input based on that feedback to achieve desired performance. This feedback mechanism allows the system to automatically correct deviations from the desired output.

In contrast, an open-loop system does not have any feedback; the system's input is provided without regard to the output, meaning the system cannot adjust itself based on output measurements.

• Servomechanism (a) refers to systems that use feedback for control, but it doesn't distinguish between open and closed-loop systems on its own.
• Output pattern (c) and input pattern (d) do not inherently distinguish between open and closed-loop systems; both systems can have varied input and output patterns.

Thus, the key distinguishing feature is feedback.