Assume The Filament Is A Black Body At 2900 K And Ignore The Effects Of The Glass On Radiation A How Long Does The Fil 1 (328.31 KiB) Viewed 17 times
Assume The Filament Is A Black Body At 2900 K And Ignore The Effects Of The Glass On Radiation A How Long Does The Fil 2 (52.77 KiB) Viewed 17 times
Assume the filament is a black body at 2900 K and ignore the effects of the glass on radiation. a) How long does the filament need to be if it emits 100 W of energy? Assume that the filament is a flat rectangle (ribbon) of width 2 mm. b) Estimate the fraction of the light emitted from an incandescent light filament that is in the visible range. c) Would changing the filament temperature be a good way to improve the light bulb's "efficiency you calculated in b)?"
Blackbody radiation functions f λT, μm.K 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000 4200 fr 0.000000 0.000000 0.000000 0.000016 0.000321 0.002134 0.007790 0.019718 0.039341 0.066728 0.100888 0.140256 0.183120 0.227897 0.273232 0.318102 0.361735 0.403607 0.443382 0.480877 0.516014 λT, µm.K 6200 6400 6600 6800 7000 7200 7400 7600 7800 8000 8500 9000 9500 10,000 10,500 11,000 11,500 12,000 13,000 14,000 15,000 fx 0.754140 0.769234 0.783199 0.796129 0.808109 0.819217 0.829527 0.839102 0.848005 0.856288 0.874608 0.890029 0.903085 0.914199 0.923710 0.931890 0.939959 0.945098 0.955139 0.962898 0.969981
Join a community of subject matter experts. Register for FREE to view solutions, replies, and use search function. Request answer by replying!