What is typically the primary purpose of a circuit breaker?

The primary purpose of a circuit breaker is to protect circuits from overloads and faults. Circuit breakers are essential safety devices in electrical systems, designed to automatically interrupt the flow of electricity when they detect conditions such as overloads, short circuits, or ground faults. By doing so, they prevent potential damage to wiring, equipment, and reduce the risk of electrical fires.

In contrast, while regulating voltage levels is important for stable electrical supply, it is not the main function of a circuit breaker. Similarly, ensuring a constant power supply and increasing circuit efficiency are not obligations of circuit breakers. Their focus is primarily on safety and protection, making option B the most accurate choice.