Question

1I11.7.(a) What, in percent, is the typical light emission efficiency of a conventional tungsten-filament light bu (Hint: it is quite low.) (b) Explain why it is so low, with the help of an illustration: Sketch, approximately to scale the spectrum) of radiation emitted by such a light bulb. In it, draw vertical lines (or arrows) indicating the range of visible wavelengths. (c) For comparison draw, in the same axes, (i) the typical spectrum emitted by a white LED lamp and (ii) the spectrum of solar radiation arriving here on Earth. function of wavelength. Draw such, and label generously! ) Note that "spectrum" does not mean a picture of a light bulb! Rather, it means a graph of intensity as a

Answer 1