Question

Which material is used for making the filament of an electric bulb and why?

Answer 1

1. Tungsten is used for making the filament of an electric bulb.
2. The basic criteria that a material to be used as a filament must possess is that the material must emit light energy on the application of electric current and the material must not melt due to the high temperature.
3. The resistance of the tungsten is very high and hence its heats very much and consequently, light energy is produced.
4. The high melting point of tungsten (${3422}^{0}C$) ensures that it doesn't melt due to the high heat produced in it.

Thus, tungsten is used for making the filament of an electric bulb.