6F30.10-Dispersion curve of a prism

6F30.10-1 6F30.10-4 6F30.10-3 6F30.10-2

Video: Watch this demo

Utah State University demo video

Description: Using a focused white light source and a prism, a visible light spectrum is projected.
This is because light rays with different wavelengths will be refracted at different angles by the prism (chromatic dispersion)
due to the fact that the index of refraction of the prism varies slightly with the wavelength.


  • Overhead projector with attached prism
  • Cardboard slit

Setup procedure:

  1. Position projector in the class so the rainbow is on the screen.
  2. Adjust the slit until a clear, easily visible spectrum is displayed.

Demonstration Procedure:

  1. Turn on the overhead projector.
  2. Note that white light when refracted through a prism creates the dispersion curve seen (rainbow). Note that it is a continuous spectrum.
  3. When finished, turn off the overhead projector.