In a Van de Graaff generator, two materials rub together and build up equal and opposite static electrical charges. The dome gains a large but safe positive charge.
A girl stands on an insulating mat and touches the dome: the charge is equally redistributed over her and the dome. Her charged hairs repel each other, move apart and stand on end. If she touches an earthed conductor, the charge will flow to earth, discharging her hair.
When a conducting object which is earthed approaches the dome of a charge Van de Graaff generater, a spark (electrical charge) jumps across, and charge flows to earth as an electrical current.
Comments
Report