electricity

As electric current enters at cathode (tungston filament) in the fluroscent lamp (tube light), the  filament heats up due the current flow and emits electrons. These energetic electrons collides and ionizes the noble gases, i.e. argon, neon, knocking off electrons from these noble gas atoms. This makes electrons available for current to flow through the gas. The electrons flow due to the electric field between two ends of the lamp.

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