Which safety device is used to protect electrical circuits from overloads?

The fuse is a safety device designed to protect electrical circuits from overloads by interrupting the current flow when it exceeds a predetermined level. It operates on the principle that a thin wire or filament within the fuse will heat up and eventually melt when excessive current passes through it. This melting action creates an open circuit, effectively stopping the flow of electricity and preventing damage to the connected devices and wiring.

In situations where a current overload occurs, such as a short circuit or a failure in the electrical system, the fuse acts quickly to prevent overheating and potential fire hazards. It is an essential component in electrical systems to enhance safety and ensure reliable performance.

Other devices listed, like the transformer and capacitor, serve different purposes in electrical systems. A transformer adjusts voltage levels, while a capacitor stores electrical energy for various applications. A relay is used to control a circuit, often functioning as a switch. However, none of these devices provide the specific protective function against overloads that a fuse does.