Matter and Electrons
Goal: To Measure emissivity from a light bulb and determine its blackbody properties.
Be sure that you play with the two student exercises so that you understand Planck's distribution formula.
- A Crooke's radiometer (can be purchased for under $10 )
- A Leslie's cube (commercial ones can be purchased for $10-25, epending on suppliers and quality. ).
You can also make a substitute Leslie's cube using a square metal container, and painting one side matte black, one side shiny black, one side white, and leaving one side as shiny metal. It should be large enough to hold a small 40W lightbulb and socket. Make a "floor" and lid of aluminum foil to retain the heat, with a hole in the floor for the socket cord. Make a hole in the lid so that you can suspend a thermometer above the light bulb.
- Follow the instructions at Web Physics 320 Lab.
- Use the data handling instructions with the lab procedures.
ALTERNATIVE LAB Goal: to observe changes in blackbody radiation at different temperatures.
Change the temperature of the blackbody and observe what happens to the emitted light.
- Describe your experiment in sufficient detail that another similarly equipped student could perform your tests.
- Include your assessment that the light bulb acts/doesn't act as a blackbody over various temperature ranges.
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