What safety device prevents overcurrent in an electrical circuit?

The fuse is specifically designed to protect electrical circuits from overcurrent events. When excessive current flows through a circuit, it can generate heat that may damage wires, components, or even start a fire. A fuse contains a metal wire or strip that melts when the current exceeds a predetermined level, effectively breaking the circuit and preventing further current flow. This interruption protects the electrical components and ensures safety.

Transformers, while essential for altering voltage levels, do not directly protect circuits from overcurrent. A resistor limits current flow but does not provide the protective function of interrupting the circuit; if the current exceeds the rating of the resistor, it might simply overheat or fail without providing protection. Relays are used to control circuits based on specific conditions, but they also do not serve the purpose of preventing overcurrent in the way a fuse does.