Principle
The pupils should learn that between an electrically charged insulator and an uncharged electrical conductor an electrical force of attraction can also arise. The forces are of the same type as those with differently charged insulators but they can only be explained by a shifting of the charges in the electrically neutral conductor.
Benefits
- Quick and easy experiment for qualitatively understanding of electrostatic phenomena
Tasks
Why does a force act between a charged plastic rod and a non-charged metal plate? Investigate the effect of a force between a rubbed polypropylene rod and an insulated, fixed, non-charged plate.