Education and Career Forum

Why incandescent tube is more economical than bulb?

It is only how efficiently the device converts electrical energy to visible light energy, and not to other forms like heat or ultraviolet. The bulb uses a tungsten filament, whose different regions heat according to their resistances (R) following P = I*I*R for the same current I. The varying heating results in emission of all kinds of radiation, not just visible light. Whereas, a incandescent tube or a CFL is filled with a calculated mixture of gas in which electrons make transitions between fixed energy levels and gain and lose energy according to fixed rules so that a particular narrow band of wavelengths is emitted. So the energy that got wasted in say, infrared light, is now being used to give out more visible light. Note that "Tubelights" or Mercury Vapour Lamps, (these are not filled with mercury vapour), also emit Ultraviolet radiation apart from visible light.

Dear
Simply i would like to say incandescent tube takes less current than bulb . It is more stable than a bulb. thatwhy it is more bene than bulb