How does a fuse provide overcurrent protection?

A fuse provides overcurrent protection by containing a metal wire that melts when the current exceeds a safe level. This melting occurs because the wire, usually made of a material with a low melting point, heats up as current flows through it. If there is an overload or short circuit that causes the current to rise above the rated limit of the fuse, the wire will heat up to the point where it melts, effectively breaking the circuit and stopping the flow of electricity. This action protects the electrical system and connected devices from damage due to excessive current.

The design of the fuse is critical, as it must respond quickly to overcurrent conditions while remaining stable under normal operation, ensuring both safety and reliability in electrical systems.