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Homework Help: Uncertainty of Grating Constant

  1. Oct 30, 2005 #1
    All right, I have to calculate the uncertainty of the grating constant (k=1/d).

    I know that the standard deviation of my 14 values of d(spacing bewtween 2 slits in a diffraction grating) is ± 5.031x10-16 m.

    Average d = 3.403x10-6m .
    k= 2.939x105lines/m.
    How would I find uncertainty? 1/± 5.031x10-16 m?

    Im really stuck here, please help.
    Thank you.
  2. jcsd
  3. Oct 30, 2005 #2
    Well since you have 14 measurements of 'd', and those measurements yield a standard deviation of ± 5.031x10-16 m, your error in d will be the standard error. That is, your standard deviation divided by the square root of the number of measurements.
    If this is an introductory course then[tex]\Delta[/tex]K = K*([tex]\Delta R/R[/tex]) would suffice as the uncertainty in your value of K.
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