- To show charge generation using a Van de Graaff Generator.
bat used in this experiment replaces the need to have
a student volunteer as a charged object (see DEM04). Shows the same principles,
will catch the class interest and is a lot less of a fuss. You choose.
Set up the generator and insulated sphere with a separation 15 to 20 cm. Connect a grounding lead between the insulated sphere and the base of the generator.
Place the bat on the sphere of the generator, with the head towards the
class. Switch on the generator and adjust the speed. Within a few seconds
hair of the bat will stand on end, then the head and tail
will lift and finally the bat will fly off the sphere. To achieve flight
the humidity needs to be fairly low and the sphere separation just right.
If the spheres are to close together arcing will occur and if too far
apart the capacitance too low.
How does a Van de Graaff Generator work? video demonstration on Youtube
- Video created by Micheal de Podesta from the National Physical Laboratory