Definition: 1 Mark
Function: 1 Mark
Mechanism: 2 Marks
Examples: 1 Mark
A filament is a thin wire inside a bulb which is made of a resistive material.
It is responsible for the light being emitted from the bulb.
When electricity passes through the material then the filament gets heated because of its high resistivity.
When the filament is heated it releases some energy in the form of light.
Any material which has high resistivity and gets heated at a low temperature can be used as a filament.
Tungsten is currently used to make filaments of the bulbs.