Experiments in electrostatics

Experiments in electrostatics  from the Discovery Palace Museum (Paris)

We consider the metallic stage shown in Figure 1. Using an electrostatic generator, we charge it negatively up to the value of -350000 Volts. A person steps on the stage. Why do hair stand up?

First of all, for the stage to be charged negatively, electrons are deposited on it. It is considered that the generator deposits approximately 100000 billion electrons or ten to the 14th power for the stage to be charged at -350000 Volts.

The above number of electrons required to charge the stage at -350000 Volts is considered to represent an extremely low number. If one wants to use this quantity to power a pocket lamp (which uses a small battery), then the lamp would be on for a tiny fraction of a second. Powering it for one second requires a much bigger number of electrons.


The person that will step on the stage will be charged negatively as electrons will be deposited on him/her. As the entire body is being charged negatively, hair are also being charged negatively and are repelled by the negative head, while individual hairs also repel each other.

It is considered that 100 billion electrons are deposited on the person. The electrons and protons of the human body are ten to the 28th power.


Figure 1