A circuit requires an unbroken path of a conducting material, such as metal wire, for current to flow. This circuit is short of wire.
To complete the circuit we add in the missing piece of wire. We know that the conducting path is complete because the light is on.
If the light filament burns through the light goes out because the circuit is no longer complete.
A circuit requires an unbroken path of a conducting material, such as metal wire, for current to flow. This circuit is short of wire.
