What does a fuse do when the current exceeds safe levels?

A fuse is a safety device designed to protect electrical circuits by preventing excessive current from flowing through them. When the current exceeds a specified safe level, the fuse responds by melting its internal wire or filament. This melting effectively breaks the circuit, interrupting the flow of electricity and preventing potential damage to connected appliances or further hazards, such as electrical fires.

The importance of this mechanism lies in its ability to act swiftly in response to overloads or short circuits, ensuring that the electrical system remains safe and functional under normal operating conditions. By breaking the circuit, it protects not only the wiring and devices but also the users, making it a crucial component in electrical safety systems.

Other options do not align with the function of a fuse. A fuse does not increase electrical flow, boost circuit performance, or change the circuit voltage; rather, its primary function is to limit current to safe levels by breaking the circuit when necessary.