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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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  video  - Kinds of Charge and Charging
  video  - Attraction and Repulsion Between Charged Objects
  video  - Charging by Induction
  video  - Lord Kelvin's Water-Drop Electrostatic Generator
  video  - Wimshurst Machine
  video  - Fun Fly Stick
  video  - Xerox
  video  - Fluorescent Bulb in Faraday Cage
 Electric Fields And Potential
 Current and Resistance
 Electromotive Force And Current
 DC Circuits
 Magnetic Materials
 Complex Circuits
 Semiconductors And Tubes
 Transmission Lines and Antennas

 video  - Charging by Induction


To demonstrate charging of objects by induction.


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Use the "Faraday Ice Pail "cage as a reliable electroscope that also measures the charge sign.

Rub Teflon stick on silk (Teflon = negative charge) or glass/Lucite on Teflon wrap (glass/Lucite = positive charge) and transfer it to the "Pith Ball on a Stick" by touching. Measure the charge with electroscope.

Next, reset the electroscope (ground Faraday cage w/ lever) and charge the "Pith Ball on a Stick" by induction. Do so by short circuiting the pith ball to the grounded outer metal cage. Bring the charged object close and "disconnect" the ground by removing the "Pith Ball on a Stick" from the outer cage. Demonstrate on the electroscope that the charge on the ball is now opposite to what it was while charged by touching.