What is Fuse ?      

    Fuse is a piece of wire of a material with a very low melting point. When a high current flows through the circuit due to Overloading   or a Short circuit , the wires gets heated and melts. As a result, the circuit is broken and current stops flowing.
                                                                       

     It must be remembered that fuse wire is always connected to the LIVE wire.

    Properties Of  Reliable Fuse :-

            Fuse must be of  correct value. For example, In a 15A circuit, the fuse wire used is thick and of 15A rating.