What is a key difference between fuses and circuit breakers?

Fuses and circuit breakers serve the same primary purpose: protecting electrical circuits from overloads or short circuits. However, a key difference lies in their reusability. Fuses contain a metal wire or element that melts when excess current flows through it, thereby breaking the circuit. Once a fuse has blown, it cannot be reused and must be replaced to restore functionality in the circuit.

In contrast, circuit breakers are designed to be reset. They can be flipped back on after they have tripped due to an overload, allowing them to be used multiple times without replacement. This design makes circuit breakers generally more convenient in electrical systems, as they don't require frequent replacements like fuses do.

Understanding this difference helps in grasping the operational aspects of both devices and their application in safeguarding electrical systems, reinforcing why the option that states fuses are not reusable is the correct answer.