What are used to protect against harmful overloads in electrical circuits?

Fuses and circuit breakers are essential components used in electrical circuits to provide protection against harmful overloads. When there is a sudden surge in electrical current, such as from a short circuit or when too many devices are connected to a single circuit, these protective devices act to interrupt the flow of electricity.

Fuses contain a metal filament that melts when the current exceeds a certain level, thus breaking the circuit and preventing further current flow. Circuit breakers serve a similar purpose but are resettable; they trip and stop the current flow during an overload but can be manually or automatically reset once the issue is resolved.

This mechanism not only prevents damage to electrical devices but also helps mitigate fire risks associated with overheating wires or components in the circuit, making them critical for electrical safety.

The other options, such as transformers, rectifiers, and capacitors, serve different functions in electrical systems—transformers modify voltage levels, rectifiers convert alternating current to direct current, and capacitors store and release electrical energy, but none of them are specifically designed to protect against overloads.