What happens to a fuse when it experiences an overcurrent?

When a fuse experiences an overcurrent, it melts and breaks the circuit. This melting occurs because fuses are designed to protect electrical systems by interrupting the flow of electricity when the current exceeds safe levels. The metal inside the fuse has a specific melting point, and when the current exceeds this threshold, the heat generated causes the metal to melt. This interruption is crucial as it prevents potential damage to connected devices, reduces the risk of fire, and maintains the integrity of the electrical system.

The other options don't accurately describe the functioning of a fuse under overcurrent conditions. For instance, a fuse does not cool down quickly nor does it strengthen its conduction; rather, it is meant to reliably break the circuit when necessary. Continuing to allow current flow contradicts the very purpose of a fuse, which is to provide protection by halting current in situations that could cause damage or create hazards.