Question: What is the primary characteristic of a closed-loop control system?

Options:

1. It does not use feedback.
2. It uses feedback to compare the actual output with the desired output.
3. It is always unstable.
4. It cannot be controlled.

Correct Answer: It uses feedback to compare the actual output with the desired output.

Solution:

Closed-loop systems utilize feedback to adjust their output based on the difference between the actual output and the desired output.