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Homework Help: 2-Slit Intensity Pattern

  1. Sep 29, 2010 #1
    1. The problem statement, all variables and given/known data

    Surprisingly, large interference effects can occur even when one of the interfering sources is
    not very probable. In the two-slit interference experiment, if one slit is “stopped down” so that
    the intensity of the wave getting through is reduced by a factor of 100 (relative to the other
    slit), show that the intensity maximum of the pattern is still (roughly) 50 per cent higher than
    at a minimum.

    2. Relevant equations

    [tex]\psi[/tex]2 = A*ei(kr1 - wt)

    [tex]\psi[/tex]1 = A*ei(kr2 - wt)

    3. The attempt at a solution

    I'm assuming that we add the 2 wave equations to find [tex]\psi[/tex]total.
    Since 1 slit has 1/100 the intensity of the other and since I is proportional to A2
    then the amplitude of reduced-intensity wave would have A= 1/10000?
  2. jcsd
  3. Sep 29, 2010 #2

    This assumption still works well for double-slit interference experiment :smile:

    You should check your calculation. Areduced = A/sqrt(100).
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