Ask a Teacher

Search



draw the fluorescent lamp and explain?
Ans :
Fluorescents are  light sources which uses the phosphors excited by electrons to create light. 
  A fluorescent lamp tube is filled with a gas containing low pressure mercury vapour and noble gases.In the typical system consists of a pair of filament emitters  one at each end of the tube.It is heated electrically and  used to emit electrons which excite the noble gases and the mercury gas by impact ionisation. A special electronic circuitry is needed to start the lamp and maintain currents at adequate levels.  The chemical composition of the coating determine the  emitted spectrum.
 Advantages are : Energy efficient,Long life,Good selection of desired color
Disadvantages are : Flicker of the high frequency may be irritating to humans,a small amount of mercury in present inside the tube.


              


comments powered by Disqus