Hello there if anyone could help me out with this question I would very much appreciate it. (Note this is my first post)(adsbygoogle = window.adsbygoogle || []).push({});

For my optics lab Fraunhofer(single slit) diffraction patterns were observed(measured distance to screen(x) and had readings for intensity in the y direction.) I converted the y distances into degrees by taking inverse tangent (y/x). So for horizontal values I have my theta and vertical values my intensity. The experiment looks like this

http://physics.wpi.edu/wiki/images/...ffraction.GIF/180px-SingleSlitDiffraction.GIF

<br><img src="http://physics.wpi.edu/wiki/images/thumb/5/5e/SingleSlitDiffraction.GIF/180px-SingleSlitDiffraction.GIF" /><br>

Anyway for my data, when plotted, I had the standard gaussian looking bell curve(i know it isnt a gaussian curve, but right now i cant think of better words to describe this). It looks like this

http://cnx.org/content/m12915/latest/SingleSlitDiffraction__3.png

<br><img src="http://cnx.org/content/m12915/latest/SingleSlitDiffraction__3.png" [Broken] /> <br>

I was wondering how I calculate the uncertainty for these results. My professor mention a Chi-Square was possible. I dont see how I could calculate the theoretical value, even when I used the value for my experiment maximum intensity at I(0), for this experiment. This is the formula I am using for Fraunhofer approximation

I(ϴ)=I(0) {sin(∏D(sin(ϴ)/λ) / (∏D(sin(ϴ)/λ) )}^2

Where I(0) is the intensity for Ө=0(maximum intensity), λ is the wavelength, and D is the slit width.

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# Homework Help: Chi-Square in Fraunhofer Approximation Lab Report

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