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If 5% of the energy supplied to an incandescent light bulb is radiated as visible light, how may visible light photons are emitted by a 100W bulb? Assume the average wavelength of all visible photons to be 5600Å. Given h=6.25xx10^(-34)Js. |
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Answer» Solution :Here `lamda=5600Å=5600xx10^(-10)m,h=6.625xx10^(-34)JS` Energy of photon, `E=(hc)/(lamda)=(6.625xx10^(-34))/(5600xx10^(-10))=3.549xx10^(-19)J` Visible energy radiated by the bulb per second `=(5)/(100)xx100=5J` `:.` Number of visible photons EMITTED per second `=(5)/(3.549xx10^(-19))=1.41xx10^(-19)` |
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