How to distinguish the charge carry by different object after rub by something??

henry407

1. The problem statement, all variables and given/known data
How to distinguish the charge carry by different object after rub by different things??


2. Relevant equations
Nope~


3. The attempt at a solution
I do the experiment in the school, but every group got different answers,. So I hope someone chould give me the theory about my question, thanks~~

Simon Bridge

Please describe the experiment.

Historically it has been very difficult to determine the charge that gets transferred when different items get rubbed. Initialy it was thought that there were two kinds of electricity - the kind you get rubbing resin and plastic, and the kind you get rubbing glass.

Careful experimentation can show you that these two are opposites of the same thing - so that it is useful to think of one as the presence of something and the other it's absence. However, which it was took a long time to work out.

Wikipedia has an overview and history.
http://en.wikipedia.org/wiki/Electric_charge