Modern Physics > Quantum Effects > Blackbody Radiation DCS# 6B40.10
VARIAC AND LIGHT BULB
incandescent light and diffraction grating
APPARATUS
showcase bulb 202-21-B
socket and variac 202-21-B
set of diffraction gratings 202-21-E5

DESCRIPTION
Distribute diffraction gratings to students.  Turn up voltage to bulb to show increasing intensity of blue end of spectrum with increasing temperature of filament.


NOTES
One can use blue and red filters (202-21-E4) to show that the change in intensity is not the same for each color.