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Lecture Demonstrations Laboratory


The Demonstrations Manual


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Electrostatics
Electric Fields And Potential
Van de Graaff Generator
Electrostatic Bell
Electric Lines of Force
Electrostatic Motor
Electric Fields
Gauss' Law
Radio in Faraday's Cage
Lightning Rod
Electric Wind
Ionic Drive
Smoke Precipitator
Capacitance
Current and Resistance
Electromotive Force And Current
DC Circuits
Magnetic Materials
Magnetism
Inductance
Induction
Complex Circuits
Semiconductors And Tubes
Transmission Lines and Antennas

Electric Fields

Purpose:

To show the electric lines of force in different electric fields.

Procedure:

Cover bottom of bowl with about 1/4 inch of oil and felt mixture and place on overhead projector. Put clamps on edge of bowl and insert electrodes of your choice. Connect wires from clamps to power supply and turn on. It takes about 10-15 seconds for the supply to generate high voltage. The felt will become polarized and migrate along the electric lines of force showing clearly the geometry of the field.

The felt and oil mixture should be remixed in the bowl before attempting a new electrode configuration

Hints:

Using a metallic mixing tool (there is a strip of aluminum for this purpose) helps to reduce charge buildup on the apparatus during consecutive uses. Also, make sure you mix well the oil & felt mixture just before doing a new electrode configuration demo. If the felt is let to settle, it will sit on the bottom of the glass dish and not move when electrifyiing the system.

Comments:

If you have a suggestion for the use of this demo which might benefit others, you can enter it below.

Equipment:

  • Overhead Projector
  • Alligator Clips
  • Connecting Wires
  • Large Flat-Bottomed Bowl
  • Oil
  • Electrodes with Clamps
  • shredded felt
  • 10kV Power Supply