Have you experienced rubbing your feet on carpet just to reach out to someone and give them a little zap? Or slide down a plastic slide and gotten a nice jolt from it? What about rubbing a balloon on your head to make your hair stand on end? A Van De Graaf generator is a tool to experience even more static electricity!
Static electricity is an imbalance of electric charge on a surface. The charge remains imbalanced until there is an electric current or an electrical discharge. A Van De Graaf generator works much the same as rubbing your feet on the carpet to move electrons throughout your body. A moving belt in the generator accumulates an excess of electric charge which is then transferred to a large hollow sphere.
The sphere builds up free electrons which all have a negative charge. When too many negative charges are near one another they will start to repel. If you force enough of them onto a single surface you can build up enough charge to see an effect such as your hair standing on end, pie tins flying off due to repulsion, or a shock!
Electricity will take the path of least resistance and wants to be neutral. As shown here, a fun and safe way to manipulate the static electricity is with a grounding rod. The grounding rod neutralizes the Van De Graaf generator by moving all of the excess charge from it to the surface of the Earth.
You can also neutralize the generator without a grounding rod. Humans are decent conductors of electricity. This means that your body could act as a grounding rod too. Just remember that you have one thing that a grounding rod does not…NERVES. If you decide to ground the sphere, brace yourself for quite the jolt!
Written by: Mimi Garai