Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Separation of two wavelengths in a diffraction grating.

  1. May 9, 2010 #1
    1. The problem statement, all variables and given/known data
    Light with two wavelengths (510.0 nm and 525.6 nm) is spread by a diffraction grating. On a screen 4 meters behind the grating we observe that the diffrence between the two second order maximum is 1 cm. What is the grating constant (d) ?

    2. Relevant equations
    I think i only need Snells Law for this problem, and some geometry.

    3. The attempt at a solution
    Im having som problem with the geometry of the solution. I need to find the distance to one of the maximums from the zero order maximum. Ive found the relations:
  2. jcsd
  3. May 9, 2010 #2
    Snell's law? You might want to use the formula for maxima's of a diffraction grating:

    [tex]d \sin \theta_m = m\lambda[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook