|
CHARACTERISTICS OF
BLACKBODY RADIATION |
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| (1) | Etotal [ergs s-1 cm-2 ] = σT 4 (Stefan-Boltzmann Law) |
| (2) |
λmax of B(λ)=
hc/kxT [where x is the root of the equation x =
5(1-e-x)]
=
0.290 cm /T, or λmax of B(ν)= hc/(3kT) = 0.480 cm/T (Wien's Law) |
| (3) | As T increases, intensity increases at all wavelengths |
| (4) | Intensity is non-zero at all wavelengths for all T > 0 |
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Planck's Law: Iν = (2hν 3/c2)/(ehν/kT -1), where c = 2.9979 ´ 1010 cm/s (speed of light), h = 6.6261 ´ 10-27 erg·s (Planck's constant), k = 1.3807 ´ 10-16 erg/K (Boltzmann's constant), ν = frequency in Hz, T = temperature in Kelvins Iν = intensity in ergs s-1 cm-2 sterad-1 Hz-1 and σ = 2π5k4/(15c2h3) = 5.669 ´ 10-5 erg cm-2 s-1 K-4. |
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