GCSE Physics: The Van de Graaff Generator

If you place your hands on the Van de Graff generator when the dome has been charged, the curren will jump from the dome to your hands, giving you a shock. The persons hair will stand on end because the charges are the same and they repel each other. Before you take your hands off, the current is earthes by using a second earthed ball. This process called earthing allows the charge to be neutralised, making it safe to take your hands off the dome. If a metal ball is placed near to the dome, the charge, if high enough will jump from the dome to the ball. You can see a spark between the ball and the dome when this happens. The belt does not touch the brushes. The roller rouches the belt, which becomes positively charged as the two rub against each other. The electrons are attracted to the belt, these go through the rush and cause the charge.