What is the primary purpose of a circuit breaker?

The primary purpose of a circuit breaker is to protect circuits from overloads. When excessive current flows through a circuit, a circuit breaker interrupts the electrical flow, thereby preventing potential damage to wires, devices, and equipment. This interruption occurs automatically when the current exceeds a predetermined threshold, reducing the risk of overheating, fires, and other hazards associated with overload conditions.

The design of a circuit breaker ensures that when it trips due to overcurrent, it does so to restore safety and protect the electrical system as a whole. This is essential for maintaining reliable and safe operation in any electrical installation, especially in industrial settings where equipment is critical and high currents can be present.

Other options focus on aspects that do not align with the primary function of a circuit breaker. For instance, allowing more current to flow or increasing voltage supply goes against the safety function of a circuit breaker, which is to prevent excess flow. Lowering electrical resistance may involve other components or methods but is not a role of circuit breakers. Thus, the correct choice aligns directly with the safety and protective function that is integral to the operation of electrical systems.