Question

What is the working principle of an electrical fuse?

• A. Ohm’s law
• B. Joule’s law of heating
• C. Coulomb’s law
• D. Faraday’s law

Answer 1

The correct option is B

Joule’s law of heating

Electric fuse works on the principle of the heating effect of electric current. It is placed in series with the device. A fuse consists of a piece of wire made of a metal or an alloy of an appropriate melting point, for example, aluminum, copper, iron, lead etc. If a current larger than the specified value flows through the circuit, the temperature of the fuse wire increases. This melts the fuse wire and breaks the circuit.