Process of tube light
A tube light or fluorescent lamp is a kind of light that uses a combination of electricity and mercury vapour to create light energy. A fluorescent light does not begin to produce light immediately, because it takes time to apply high voltage to its electric poles, after which, this energy needs to be stabilised. When you turn on the switch, the discharge begins in the starter. The heat makes the bimetallic poles in the starter bend towards each other. Once the bimetallic poles meet, the discharge automatically stops and is sent to the poles of the lamp.
When the bimetallic strip cools, it returns to its original position. Meanwhile, the built up current is transferred to the poles of the tube, vapourizing the mercury droplets. The mercury gas is then ionized by the current flowing within.
Why a Tube Light produces White Light?
The electricity causes tiny particles, called electrons, to travel at high speeds between the poles. These electrons hit the mercury gas, producing ultraviolet radiation. Since the human eye is unable to see this radiation, the glass tube is coated with a fluorescent material which changes it into white light.
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