- #1
germblaster
- 5
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How does one calculate efficiency for an incandescent light bulb? Assume the bulb is 40 W, has a tungsten filament at temp. ~ 2800 K. The bulb would be used for heating in a device.
If we assume blackbody:
From Wien's displacement law, the maximum wavelength is 9.99E-7 m. Fromt the blackbody curve for this temp., it appears that only ~10% of the radiation is emitted in the visible spectrum. Does this mean that the rest goes into heating?
Is if safe to assume an efficiency of greater than 90%?
If we assume blackbody:
From Wien's displacement law, the maximum wavelength is 9.99E-7 m. Fromt the blackbody curve for this temp., it appears that only ~10% of the radiation is emitted in the visible spectrum. Does this mean that the rest goes into heating?
Is if safe to assume an efficiency of greater than 90%?