Answer to Question #147131 in Physics for Noor

Question

what is the function of a fuse wire and how it works in a residential circuit?

Answer 1

A fuse provides a built-in fail-safe to the electrical circuit for a device. The fuse contains a thin wire that will melt if the current gets too high. If there is a fault that causes the casing of the device to become live, a large current will flow through the live wire and low-resistance earth wire. This high current will cause the fuse to melt.

Once the fuse has melted, the circuit is broken and no more current flows through the device. This means the case of the device is no longer live and there is no more risk of electrocution. A circuit breaker can serve the same function as a fuse but can be reset without the need for replacement if it trips.