What does a circuit breaker do?

A circuit breaker plays a crucial role in electrical systems by automatically stopping the flow of electricity in an overloaded circuit. This function is essential for safety, as it protects electrical circuits from damage caused by excessive current, which can lead to overheating and potential fire hazards. When the current exceeds a predefined limit, the circuit breaker trips, interrupting the electrical flow and preventing further damage or danger.

This automatic mechanism not only safeguards electrical appliances and wiring but also contributes to the overall safety of the electrical system. In contrast, other options do not accurately reflect the purpose or function of a circuit breaker. For instance, increasing voltage, enhancing electrical connections, or filtering electrical noise are not functions associated with circuit breakers, making the correct answer focused solely on their preventive capabilities during overload situations.