About Electrostatics

Electrostatics is the branch of science that deals with the phenomena arising from stationary or slowly moving electric charges. Electrostatic phenomena include many examples as simple as the attraction of the plastic wrap to your hand after you remove it from a package, to the apparently spontaneous explosion of grain silos, to damage of electronic components during manufacturing, to the operation of photocopiers. Electrostatics involves the buildup ofcharge on the surface of objects due to contact with other surfaces.

An electroscope is an early scientific instrument that is used to detect the presence and magnitude of electric charge on a body. It was the first electrical measuring instrument. The first electroscope, a pivoted needle called the versorium, was invented by British physician William Gilbert around 1600. The pith-ball electroscope and the gold-leaf electroscope are two classical types of electroscope that are still used to demonstrate electrostatics.

A Van de Graaff generator is an electrostatic generator which uses a moving belt to accelerate very high electrostatically stable voltages on a hollow metal globe on the top of a stand. Invented in 1929 by American physicist Robert J. Van de Graaff, the potential differences achieved in modern Van de Graaff generators can reach 5 megavolts. The Van de Graaff generator can be thought of as a constant- current source connected in parallel with a capacitor and a very large electrical resistance.

The Wimshurst machine is an electrostatic device for generating high voltages developed between 1880 and 1883 by British inventor James Wimshurst (1832 - 1903). It has a distinctive appearance with two large contra-rotating discs mounted in a vertical plane, two cross bars with metallic brushes, and a spark gap formed by two metal spheres.