Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography

PLEASE REQUEST DEMOS WELL IN ADVANCE

Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.

Choose a Topic or Enter a keyword to search:

Mechanics
Fluid Mechanics
Oscillations And Waves
Thermodynamics
Electricity And Magnetism
Optics
Modern Physics
Audio-Visual
New or Modified Entries (within the last month)

I cannot find what I want!

You have selected the following Demos:

None Selected

Choose a subtopic:
(Clicking a green button will add that demo to your list)

Quantum Effects: video - Photoelectric Effect in Zinc; Stopping Potential; Photoconductor (resistor); video - Electron Diffraction; Quantum Levitation (Flux Pinning)
Atomic Physics
Nuclear Physics

Photoconductor (resistor)

Purpose:

To demonstrate the operation of the photoconductor (photoresistor). Photoconductor is a poor semiconductor in which the conduction and the valence band are so closely spaced that a visible light source provides enough energy to the electrons to switch the bands thus reducing the sample resistance with brighter light.

Procedure:

Connect the photo resistor apparatus to a DC voltmeter. Apparatus is just a pot resistor connected in series with the photo resistor. By shining the light on the photo resistor the voltage drop across the pot increases.