This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: PHYS122 2010W Assignment 6 Due: 17:00 Thursday 20100304 PHYS122 Assignment 6 UW User ID: Your UW User ID is not the same as your Student Number. Surname: Given Name: 1. (a) (2) Consider the quantity x = hc/λk B T . For what wavelength, λ long , will x be one at room temperature? λ long = (b) (2) What “colour” does this correspond to? (c) (2) Assuming that x as defined in (a) is small, perform a binomial expansion on the exponential in Planck’s Law, I ( λ,T ) = 2 πhc 2 λ 5 ( e hc/λk B T 1 ) , and so find an expression for the long wavelength limit of the spectral radiance. I ( λ,T ) ≈ Page 1 of 5 PHYS122 Assignment 6 UW User ID: Your UW User ID is not the same as your Student Number. Surname: Given Name: (d) (1) Replace the wavelength, λ , with x as defined in (a) in Planck’s expression for the spectral radiance. Calculate the derivative of the resulting expression for the spectral radiance with respect to x and so find an expression for x at which the spectral radiance is an extremum.is an extremum....
View
Full Document
 Winter '10
 O'Donovan
 Physics, Fundamental physics concepts, UW User ID

Click to edit the document details