PURPOSE: To show induced dipole attraction and induced dipole repulsion.
DESCRIPTION: A Wimshurst machine produces a high potential difference, one side of which is connected to a conducting sphere and the other side connected to a person blowing bubbles, forming an electric dipole.
The bubbles attain the charge of the person blowing them. They're attracted to the charged dome and follow the electric lines of force to the sphere, which has the opposite charge. A few bubbles will actually touch the sphere first and pick up the charge on the sphere. Once charged by the sphere they will be repelled and burst, causing charged ions to spray onto the other on-coming bubbles. Once sprayed by the charged ions the on-coming bubbles will suddenly stop, reverse direction and run away repelled.
EQUIPMENT: Van de Graaf and the stand are stored in the electricity and magnetism cabinets. the soap bubbles are stored in the chemical cabinet by the sink.
SET UP TIME: None.