A fuse is a safety device used in an electrical plug - Leaving Cert Physics - Question (k) - 2022

A fuse is designed to protect electrical circuits by preventing excessive current flow. It contains a thin strip of metal that has a specific melting point.

1. Normal Operation: Under normal operating conditions, the current flowing through the fuse is within safe limits, allowing the metal strip to remain solid.

2. Excess Current: When there is a fault in the electrical circuit, such as a short circuit or overload, the current increases dramatically.

3. Melting Process: Once the current exceeds the fuse's rated capacity, the heat generated by the increased current causes the thin metal strip to melt.

4. Circuit Interruption: As the metal strip melts, it breaks the circuit, stopping the flow of electricity and thereby protecting the connected devices from damage due to excess current.