More on Static Electricity (GCSE Physics)

More on Static Electricity

Van de Graaff Generators

A Van de Graaff generator is a device you may have used at school to generate static electricity.

A motor is used to turn the rubber band, creating friction between the rubber band and the rollers. This causes charge to build up, which sits on a metal dome.

The generator removes electrons, so only a positive charge remains on the dome. This creates a force which will act upon any charged particle within the electric field surrounding the dome.

If a negatively charged sphere is placed near the dome, a spark will be produced due to the movement of electrons.

Remember we learnt that static electricity is a non-contact force. This means that you can feel an effect without even having touched the dome.

If you try touching the dome of a Van de Graaff generator at school, you may notice that your hair starts to stick out from your head in different directions. This is because your hair starts to lose electrons and become positively charged. Since the rest of your body is also positively charged and like charges repel, your hair will be repelled from your head and the other strands of hair.