Two approximations to Planck's Law are useful in the extreme low and high limits of (lambda T).
Question:
Two approximations to Planck's Law are useful in the extreme low and high limits of \(\lambda T\).
a. Show that in the limit where \(\left(C_{1} / \lambda T\right) \gg 1\) that Planck's spectral distribution reduces to the following form:
\[E_{b \lambda}(\lambda, T) \approx \frac{C_{o}}{\lambda^{5}} \exp \left(-\frac{C_{1}}{\lambda T}\right) \quad \text { Wien's Law }\]
Compare this result to Planck's distribution and determine when the error between the two is less than \(1 \%\).
b. Show that in the limit \(\left(C_{1} / \lambda T\right) \ll 1\) Planck's distribution law reduces to:
\[E_{b \lambda}(\lambda, T) \approx C_{2} \frac{T}{\lambda^{4}} \quad \text { Rayleigh-Jeans Law }\]
Compare with Planck's distribution and determine when the two are in error by less than \(1 \%\).
Step by Step Answer: