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Physics Honors/AP 1 and 2

LAB: Diffraction Grating and Wavelength

Course Materials are always under revision! Weblecture content may change anytime prior to two weeks before scheduled chat session for content.

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Physics Lab

The Wave Nature of Light

Goal: Use diffracting grating to determine wavelength



  1. Set up your apparatus as shown below:
    Diffraction Setup
  2. Determine your values for the diffraction grating.
  3. Measure L and x to the first (and if possible, second or third) maxima.
  4. For each maxima, use the relationships shown to calculate the wavelength.
  5. Average your values.

Data Handling

  1. Present your data in tabular form.


  1. Along with the usual materials, procedure, setup, and data, show your calculations of wavelength and determine whether this is a reasonable wavelength for a ruby laser.

Post your report to the Lab thread at the Moodle.