What is an electric fuse? Explain its fabrication. function and use in electric circuit in detail.

Explanation

An electric fuse is a low resistance resistor Wire having low melting point that provides protection in the event of a overload current.
The fuse is placed on live Wire in series With the device (and With the mains supply).
The fuse is a safety device used in electric circuits which protects circuits and appliances by stopping the flow of any unduly high electric current.
If consists of a piece of wire made of a metal or an alloy of approprlate melting point e.g., aluminium, copper,iron,lead,etc.
If a current higher than the specified value flows through the circuit, the temperature of the fuse Wire increases. This melts the fuseWire and breaks the circuit, due to which current stops flowing.
The fuse used to protect an individual electrical device is shown in figure.

The fuse connected in series with the mains supply is generally encased in cartridge of porcelain or similar material with metal ends.
The fuses used for domestic purposes are rated as 1 A, 2 A, 3 A, 5 A, 10A, etc.
For an electric iron which consumes 1 kW electric power when operated at 220 V. a current of `I=P/V =1000/220= 4.54 A` flows in the circuit.
In this case, a fuse of rating 5 A should be used.