Purpose:Demonstrate continuous spectrum as the brightness of the source changes
Description: A bright white light source is directed through a series of lenses and a prism to provide a continuous white light spectrum. The intensity of the source bulb is adjusted using a variable transformer on the input to the light source.
• Encourage students to predict how changing the input power will change the spectrum. Will the spectrum grow uniformly brighter and dimmer, or will there be a change in what colors we see in what proportions?
As the light intensity is decreased, the spectrum becomes less intense but also shifts significantly toward the red. Increasing the source intensity, and thus the blackbody temperature, shifts the spectrum to the blue as the intensity increases.
Availability:Primary demonstration apparatus being repaired, but substitute apparatus available.
Loc codes:OM1, LS1, PS1, FS0
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Last modified on Wednesday, 16 June 2021 16:50