Question

Describe how a fluorescent light works.

Answer 1

Light is produced in fluorescent lamp as a result of flow of free electrons and ions inside a gas which consists of a glass tube coated with phosphor and containing a pair of electrodes at each end. It is filled with an inert gas and consists of mercury liquid.

As current enters the tube through the electrodes, the current passes through the gas conductor, in form of free electrons and vaporizes the mercury. As the electrons collide with the gaseous atoms of mercury, they give away free electrons which jump to higher levels and when they fall back to their original level, photons of light are emitted. However, this is not visible to us. When this light strikes the phosphor coated on the tube, it excites the electrons of phosphor to higher level and as these electrons fall back to their original level, photons are emitted and this light energy is now in form of visible light