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Which formulas are appropriate for calculating intensity?

  1. Aug 4, 2017 #1
    1. The problem statement, all variables and given/known data
    Monochromatic plane waves of wavelength 537nm are incident on two narrow slits and produce an interference pattern on a wall 3.1m away. The slits are spaced 26 micrometers apart and are 5.7 micrometers wide each. What is the ratio of intensity to that of the central fringe a distance of 35.5mm from the central fringe?

    2. Relevant equation


    3. The attempt at a solution

    I tried using this formula to find the intensity of the central fringe and also the intensity of the fringe 35.5mm from the central fringe, however, I could not determine what I(sub)naught was.

    Attached Files:

  2. jcsd
  3. Aug 4, 2017 #2

    Charles Link

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    Homework Helper
    Gold Member

    Your formula is correct, as you have it in the link. You left out the exponent of 2 when you typed it out. They simply want you to compute the ratio ## \frac{I}{I_o} ##. You should be able to do that using your formula. (Usually the letter ## x ## is used instead of ## z ## in this formula. In any case, ## z=35.5 ## mm). You should be able to figure out what ## d ##, ## L ## and ## \lambda ## are.
    Last edited: Aug 4, 2017
  4. Aug 4, 2017 #3
    That makes so much sense! Thanks a lot for your time!
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