Question

how fuse wire is connected in household circuit

Answer 1

A fuse is connected in series at the begining of the circuit. The purpose of a fuse is to prevent overcurrent from damaging the load or other parts of the circuit. A series connection ensures that any current that enters the circuit passes through the fuse before reaching the load (a bulb or fan or anything that uses the current to perform work). In case of an overcurrent the fuse breaks the circuit thereby preventing the circuit from any damage..

Answer 2

they are connected in series to prevent overcurrent in the components by this, when the fuse blows it will it will open whole circuit and stop the flow of current through the components.