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Al Tobias (wat4y) - Office: Rm. 201, (434) 924-0538 - Lab: Rm. 202, (434) 924-6800

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography

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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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Electrostatics: 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
Capacitance
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Inductance
Induction
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video - Wimshurst Machine

Purpose:

Show a working example of a Wimshurst machine and explain how the electrostatic generator charges by induction.

Procedure:

DEMO VIDEO DOWNLOAD w/ sound / 854x480 / 5.69Mb/s / 153MB size

The polarity of an induction (influence) generator is not necessarily determined ahead of time. However, it can be determined at the time of use by:

looking at the direction of the spark at the electrodes, it travels from NEGATIVE (-) to POSITIVE (+)
using the electrometer and conducting styrofoam ball on a stick to sample the charge on either electrode

Leyden jars can be removed from the circuit by lifting away the "switch" on top of the base.