I remember a bit vaugely : (Lamda)max * T = constant = 0.2896
Constant is Wien's constant = 0.2896 cm-deg K
So (Lamda)max = 0.2896 / 2800 = 1.034 * 10^(-4) cm.
wavelength = 1.034 * 10^(-4) / 100 meter = 1.034 * 10^(-6) m =
= 1.034 microns
2007-01-27 04:35:10
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answer #1
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answered by anil bakshi 7
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To solve this problem, we need to use Wein’s displacement law, which states that there is an inverse relationship between the temperature of a radiant object and the peak wavelength of the electromagnetic radiation (light) that it emits (i.e., the hotter the object, the shorter the peak wavelength of the light that it produces). Wein’s law states:
λmax = b/T
where:
λmax = the peak wavelength in meters (m);
b = the constant of proportionality (called Wien's displacement constant), which equals 2.8977685 Ã 10^-3 m K; and
T = the temperature of the object in degrees kelvin (K).
*Notice that you could use any unit of measurement for length (e.g., meters, centimeters, nanometers, etc.) as long as you are sure to use the same unit for both λmax and b by converting their values.
Now, inserting the numbers from your problem, we have:
λmax = (2.8977685 à 10^-3 m K) / (2800 K)
which equals 1.035 à 10^-6 m, or roughly 1 micrometer (μm), which puts it in the near-infrared band (and just below the range of human vision).
If you think about it, it’s ironic that a light bulb operating at such a temperature would be putting out most of it’s “light” energy in a form that isn’t even useful to people. Incidentally, that’s why traditional, incandescent light bulbs are considered to be so inefficient.
Cheers!
2007-01-27 04:52:02
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answer #2
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answered by Anonymous
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In the band known as visible light
Sea the Angstrom Scale for details in page ???
2007-01-27 03:34:08
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answer #3
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answered by Anonymous
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2800K is a bit low, turn the dimmer up.
2007-01-27 03:33:51
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answer #4
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answered by Del Piero 10 7
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