Which device is commonly used for overcurrent protection in circuits?

The device most commonly used for overcurrent protection in circuits is a circuit breaker. Circuit breakers are designed to interrupt the flow of electrical current when it exceeds a predetermined level, thereby protecting the circuit from damage that could occur due to overheating or potential fire hazards caused by overcurrent conditions.

They operate automatically and can be reset after tripping, making them convenient for ensuring ongoing protection without needing to replace a component like a fuse. This capability means circuit breakers not only provide safety but also contribute to operational efficiency in electrical systems, as they allow for easy restoration of power after a fault condition has been resolved.

In contrast, while fuses also serve the purpose of overcurrent protection, they are single-use devices that must be replaced after they blow. Transformers and capacitors do not act as protective devices for overcurrent conditions. Instead, transformers are used to change voltage levels in circuits, and capacitors store electrical energy for various applications, like power factor correction or coupling/decoupling signals, but they do not protect against overcurrent.