How does tubelight work ?
Hi Niharika!
A tube light works under the principle of fluorescence. The fluorescent tube contains two filaments, one at each end of the tube, which glow to heat up the gas contained inside the tube. The inner surface of the tube is coated with compound of elements such as phosphorus having fluorescence. While manufacturing, the tube is filled with a small amount of a gas such as mercury vapor (for a white color), carbon dioxide (for green), neon (for red color), etc.
The power supply is delivered to the tube through starter and choke. When the supply is turned on, the two filaments glow and the contacts of the starter becomes open. This causes a sudden change in the flux linked with the choke. Due to this sudden flux change, a high voltage is developed across the choke and is delivered to the tube. This high voltage ionizes the warmed-up gas inside the tube. This ionized gas excites the fluorescent coating inside of the tube so that it gives out visible light.
Cheers!!