Incandescent bulbs
When an electric current passes throught the metallic filament of a light bulb, it produces light. This phenomenon is called incandescence.
Fluorencent tubes
Inside a fluorencent tube, there is a metallic filamen, normally made of tungdten. There is also an inert gas, such as argon, and a small amount of mercury.
Light- emitting diodes (LED)
A light-emitting diode (LED) has layers of semiconductor materials.When electricity is applied to the LED, the electrons and holes cross over into the active layer, where they combine and produce photons, or particles.
No hay comentarios:
Publicar un comentario