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Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography


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.

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 Electric Fields And Potential
 Current and Resistance
 Electromotive Force And Current
 Visual Electricity Demonstrator and Generator
 Electrolysis of Water
 Internal Resistance of Batteries
 Fuel Cell
 Thermoelectric Generator
 Thermoelectric Magnet
 DC Circuits
 Magnetic Materials
 Complex Circuits
 Semiconductors And Tubes
 Transmission Lines and Antennas

Electrolysis of Water


To show that it is possible to separate chemical compounds into their constituent components by passing an electric current through them.


A mixture of sodium carbonate and water is placed into a flask and two electrodes inserted. The end of a tube connected to the flask is placed into a beaker containing soapy water. When the electrodes are connected to a battery, bubbles of hydrogen and oxygen form and rise to the surface. Once a few bubbles have been collected on the surface of the soapy water they can be lit with a match or piezoelectric sparker.


It may take a few seconds for the hydrogen-oxygen mixture to displace any air in the flask and tube. Salt water (sodium chloride solution) also provides enough hydrogen for a reasonable boom


  • Piezoelectric Demonstrator
  • Beaker
  • Matches
  • 6 or 12 V battery
  • Flask