0Electric lights are now used every day and night as an artificial form of light. There are several different types of electric lights including tungsten filament light bulbs, neon lights and fluorescent tubes.
Tungsten filament bulbs
Tungsten filament bulbs are cheap to make and easy to use. They contain a thin metal filament made out of tungsten (a type of metal). This filament becomes very warm when electricity flows through it and glows yellow-white. These bulbs last only about 1000 hours because the filament becomes thinner and thinner as it burns.
Neon lights
A neon light is commonly used for advertising. Neon is a gas that gives out light when high-voltage electricity is passed through it. By changing the electric current, up to five different colours can be produced in the same tube.
Fluorescent tubes
Fluorescent tubes are widely used in the office and the home. Fluorescent tubes are glass tubes that contain mercury vapour. When an electric current is passed through the mercury vapour it gives off ultraviolet light. This ultraviolet light is absorbed by phosphor powder that coats the inside of the tube and starts to glow to make a blue-white light. These lights need special electronic starters to produce the high voltage needed to start the light.
