Van de Graaff generator

Explore how to make real flying saucers!

Difficulty:
Danger:
Duration:
20 minutes

Safety

  • Carefully review the general safety advice on the back of the box cover before starting the experiment.
  • The Van de Graaff generator setup can affect the work of ICDs and pacemakers. Read the safety instructions before use.
  • Read the "Working with Batteries" section of the safety guidelines carefully before proceeding.
  • Disassemble the setup after the experiment.

Step-by-step instructions

First of all, power the Van de Graaff generator, keeping in mind the batteries’ polarity.

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Glue a foil mold to the top contact of the Van de Graaff generator. Charged particles will accumulate on it when the generator is turned on.

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Attach the foil underlay to the bottom contact of the generator. This will allow the generator to pick up more charged particles from the underlay and send them to the top contact.

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The charged particles scatter all over the foil molds, and the particles on the lower molds repel the particles on the uppermost one, sending it flying.

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Disposal

  • Dispose of solid waste together with household garbage.
  • Dispose of used batteries in accordance with local regulations.

Scientific description

Why do the foil molds  connected to the Van de Graaff generator go flying ? When the generator is running, identically-charged particles   accumulate on the molds . Particles with the same charges  repel  each other, which causes the foil molds  to push each other away . Each mold  in the stack is repelling  the top foil mold , and as soon as enough charged particles  accumulate, it flies off .Where do all these charged particles  come from? Just like in the first experiment, from friction between two different materials  ! Only now, for efficiency’s sake, we’ve implemented a more complex design.

At its core, the generator consists of two axes  and a belt . When you turn on the generator, the belt  starts to move , rubbing against the axle . The generator is made of materials that allow the belt  to pick up electrons  from one axis  and give them to the other. As a result, charged particles  migrate  from the lower axis  to the upper axis .As the upper axis  is connected to the foil molds , it gives them its charged particles . In turn, the lower axis  is connected to a metal substrate , which serves as a source of charged particles . The presence of a large source increases the efficiency of the generator.