Blackbody Radiation in the Visible Spectrum

This demonstration shows how the peak wavelength of a blackbody changes with temperature. Diffraction gratings are used to view the spectrum of a bulb and as the temperature of the filament is increased, the most intense colors change.

Setup:

Place the bulb in stand and the rheostat on the demo table. Plug the lamp into the rheostat.

Distribute diffraction gratings to the students.

Turn on the rheostat and increase the voltage to change the brightness and temperature of the bulb.

View the spectrum through the diffraction grating and see how the intensity changes as the temperature changes.

Notes:

Do not leave the bulb on too long as it gets very hot.

Courses Used In:

Coming Soon

Discussion and Polling Questions:

Coming Soon

Equipment Needed:

• Projector Lamp in Stand

• Class Set of Diffraction Gratings

• Rheostat