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Homework Help: Young'a double slit experiment

  1. Mar 26, 2007 #1
    1. The problem statement, all variables and given/known data
    in a double-slit experiment, blue light of wavelength 4.60*10^2 nm gives a second order maximum or CI at a certain location P on the screen. what wavelength of visible light would have a minimum or DI at P?


    2. Relevant equations
    x=(l*lamda)/separation


    3. The attempt at a solution
    I dun get it at all
     
  2. jcsd
  3. Mar 26, 2007 #2
    The equation for double slit experiments when it is a maximum is
    sin A=m(wavelength)/d. The equation for minimums is
    sin A=(m+0.5)(wavelength)/d. Where A is the angle from where the observer will look at the spot on the screen. M is the "order" of the spots, whether it be max or min. d is the distance between the slits. Put all the constants on one side, which will be the sin A and d. Simple math and equating the equations together will get you the correct answer.

    The question is a bit of vague, since it does not say what order is the minimum.
     
  4. Mar 26, 2007 #3
    i dunno it was nelson's text book chapter 9 review Qs
     
  5. Mar 26, 2007 #4

    Doc Al

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    Staff: Mentor

    But it does say visible light.
     
  6. Mar 26, 2007 #5
    lol, i missed that ;)
     
  7. Mar 26, 2007 #6
    um..how should i start it...
     
  8. Mar 26, 2007 #7
    How should i start it!?><
     
  9. Mar 26, 2007 #8
    well, just follow the instructions in my previous post

    move the constants to one side for both equations and equate the other sides together.

    m1(wavelength1)=(m2+0.5)(wavelength2)
    you know that m1 is 2 and wavelength1 is 4.60*10^2 nm.
    Now try different values for m2 that will result in a wavelength that's between 400 to 700 nm. (visible light)
     
  10. Mar 26, 2007 #9
    oh, so when i replaced m2 to 1, i got about 600nm..i think thatz the answer.
     
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