Filament of a torch bulb is
$(a)$. a metal case
$(b)$. metal tip at the centre of the base
$(c)$. two thick wires
$(d)$. a thin wire.

AcademicPhysicsNCERTClass 6

The filament of a bulb is a thin wire that glows when the current is passed through it.

So, option $(d)$ is correct.

Updated on 10-Oct-2022 13:30:39