What best describes a closed loop circuit?

A closed loop circuit is characterized by the continuous feedback system it employs to control its operation. The essence of this type of circuit is that it relies on sensors to monitor the output of the system, allowing for real-time adjustments and corrections based on the feedback received. This means the sensor is affected by the action of the controlled device, as it senses the results or state of that device directly.

For example, in a refrigeration system, a thermostat may gauge the temperature in a space and provide feedback to the compressor to adjust its operation accordingly. This maintains the desired setpoint temperature, demonstrating the interrelationship between the sensor and the controlled device.

In contrast, the other options do not accurately describe a closed loop circuit. The first option suggests that feedback is unnecessary, which contradicts the fundamental principle of a closed loop. The third option implies that the system operates independently of control mechanisms, ignoring how the feedback loop is integral to its functionality. Lastly, the fourth option about constant voltage output does not pertain specifically to the characteristics of a closed loop circuit but rather refers to electrical outputs, which is not the main focus of a closed loop system in the context of control and regulation. Thus, the correct characterization of a closed loop circuit is the one that