Which type of energy does a fuse primarily work to protect against?

A fuse is designed to protect electrical circuits by breaking the circuit if the current flowing through it exceeds a certain threshold. This threshold is determined by the fuse's rating, which is designed to allow normal current levels to pass through without interruption. However, in the event of a fault, such as a short circuit or an overload, the current can increase rapidly, generating excess heat.

The thermal energy that arises from this increased current can result in damaging effects if not controlled, including overheating of wires and components or even electrical fires. The primary function of a fuse is, therefore, to safeguard against these potential dangers by melting the conductive element within it, which interrupts the flow of electrical energy and prevents thermal damage.

In this context, while potential, thermal, and mechanical energy have their roles in various systems, the specific protective mechanism of a fuse is fundamentally tied to electrical energy—its flow and the heat generated by excessive current. This makes the choice of electrical energy the most appropriate answer.