What is the primary purpose of a circuit breaker?

The primary purpose of a circuit breaker is to protect electrical circuits from overload and short circuits. When the current flowing through a circuit exceeds the breaker's rated capacity due to issues like a surge in demand or a fault condition, the circuit breaker automatically interrupts the flow of electricity. This function is crucial for preventing damage to wiring, appliances, and reducing the risk of electrical fires that could occur from overheating or arcing caused by excessive currents.

While other options might relate to different aspects of electrical systems, they do not accurately describe the critical role of a circuit breaker. Enhancing efficiency and measuring electrical consumption are separate functions handled by different devices and systems. Circuit breakers do not increase the power supply but instead ensure that the existing power is safely managed. Thus, the correct understanding of a circuit breaker's primary purpose centers on its role in electrical safety and protection.