Question

How does the wire in the filament of a light bulb behave differently to the other wires in the circuit when the current flows?

What property of the filament wire accounts for this difference?

Answer 1

Filament of a light bulb	Connecting wire
The wire in the filament of a light bulb has a high resistance and a high melting point. So, it heats up without melting and glows when the current flows through it.	The connecting wire in a circuit has a low resistance and a low melting point. So, it does not heat up much when the current flows through it and thus does not glow.

It is the high melting point of the filament wire that is accountable for this difference.