Demonstration Manual

Electricity and Magnetism

DEM04 - Hair-Raising Demonstration, Human Electroscope

Objective:

- To illustrate distribution of charges and lines of force of the field using a Van de Graaff Generator.

Apparatus:

• Student
• Van-de-Graaf generator
• Insulating stool (not shown)

Method:

A student (or instructor) with fine dry hair, stands on an insulating stool and places both hands on the sphere of the generator. (Make sure that the generator was previously discharged to prevent shock). When the generator is energized, the hair tends to rise and extend along the lines of force of the field about the head. After the experiment, the student must hold on to the sphere until it is discharged. Or, the aluminum sphere is moved into contact with the generator by another person, to discharge the spheres.

   Watch a Charge Demo: Van de Graaff Generator video demonstration on Youtube

- Video Created at Utah State University by Professor Boyd F. Edwards and assistants.

   Watch a How does a Van de Graaff Generator work? detailed video demonstration on Youtube

- Video created by Micheal de Podesta from the National Physical Laboratory