Can anybody explain e the basic working of tube light? Or can anybody give me the web sites to which I can refer to about the working of tube light?

Bsaically a current is passed through a gas, the electrons in the gas are excited into higher energy levels by the electricity. When the electrons relax back to the lower energy levels, they emit a photon in the ultra-violet range. On the inside of the tube is a fluorescent material which absorbs the UV light and converts some of the energy into heat and emits a lower energy light, in the visible.

That's basically how it works.