Material :
Two nails
A short length of thin iron wire(a strand of picture frame wire)
An ordinary bottle or jar
A cork to fit the bottle
Four dry cell batteries
A length of covered copper wire
Procedure :
You will see that :
The thin iron wire gets hot enough to glow and you have made an electric lamp of the bottle. However, the iron wire gets so hot that it burns in the air of the bottle. The iron breaks and the lamp goes out.
image credit
Explanation :
In our modern electric lamp, nitrogen (which doesn’t sup- port burning) is substituted for the air within the bulb. Tungsten is used for the inner (filament) wire because this metal can get white hot and glow without melting. Since it
requires less heat to make a thin wire glow, an extremely thin tungsten wire is used.