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Homework Help: Youngs double slit exp.

  1. Mar 3, 2009 #1
    1. The problem statement, all variables and given/known data
    In a Youngs dbl. slit experiment using green light the fringe width was observed to be 0.20mm.if red light replaces green light,what will be the fringe width?

    2. Relevant equations
    hmm lambda=ay/d but (no info is given on rest)=/
    wavelengths:green=5.2x10^-7m ,red=6.5x10^-7m

    3. The attempt at a solution
    well i dont know if its correct but i tried to solve it.by dividing the wavelength of of red over greens and i got 1.25m which i multiplied to (2x10^-4) <---- which is the fringe width of green .=/ i totally made it up .sos here =)
  2. jcsd
  3. Mar 3, 2009 #2
    Hey ibysaiyan,

    Your method is right but now I want you to explain why it is. What do we know about d, n and L in the equation:

    [tex] n \lambda \ = \ \frac{xd}{L}[/tex]

    in relation to this question?

    The Bob

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