PURPOSE: To illustrate the electric field for various geometries.

DESCRIPTION: Samples are mounted in a holder on an overhead projector and charged using a 2500 VDC low-current power supply. The particles in the solution become polarized and align along electric field lines. Sample geometries include oppositely charged points, plates and coaxial circles. Click your mouse on the picture above to see field lines for samples.

SUGGESTIONS: The web site Teaching Electromagnetism Using Advanced Techniques contains a number of computer-generated static and dynamic electric field examples.

REFERENCES: (PIRA 5B10.40) See Demonstration Reference File.

EQUIPMENT: Geometry samples (at left in picture) with power supply and tray of solution containing particles that can be polarized by an external electrc field, mounted on overhead projector system.

SETUP TIME: 20 min.