What is a fuse primarily designed to do?

A fuse is primarily designed to protect a circuit by melting when excessive current passes through it. This protective feature is crucial in preventing damage to electrical devices and wiring due to overcurrent conditions. When the current exceeds a certain predetermined level, the metal within the fuse heats up and melts, effectively interrupting the circuit. This action stops the flow of electricity, which helps to avoid potential hazards such as overheating, fires, and equipment failure.

This characteristic of the fuse is fundamental to electrical safety systems, as it acts as a fail-safe mechanism that safeguards both the equipment and the connected circuits. By ensuring that excess current does not continue to flow, fuses play a vital role in maintaining the integrity and reliability of electrical systems.