Ganariba

History
The Van de Graaff Generator was invented in the Princeton University labs around 1929 by Robert
J. Van de Graaff. He had used Wimshurst machines to generate positive ions for experiments,but
realized that he needed far higher potentials.
Around 1933, while at M.I.T., he constructed his giant “twin” generator in a dirigible
hangar in Dartsmouth, Massachussetts. Another largegenerator, built by Van de Graaff in 1931, is
now housed in the Boston Museum of Science, where it is used for daily shows .
Supposedly, the first electrical generator was a device constructed by OttoVon Guericke in the 17th
century in Germany. His “generator” was simply a ball of sulphur on a stick. When the ball was
rotated and a hand or leather pad was brought into contact with it, thefriction created static electricity.
Later machines used rotating glass cylinders , then rotating glass disks. Many permutations of the basic friction machine occurred as experimenters tried to increasethe voltages and currents their apparatus could produce.
Important concepts
* Electrostatics: is the branch of physics that deals with the phenomena and properties of stationary orslow-moving (without acceleration) electric charges.
* Electric energy:  is energy newly derived from electrical potential energy. When loosely used to describe energy absorbed or delivered byan electrical circuit for example, one provided by an electric power utility "electrical energy" refers to energy which has been converted from electrical potential energy
* Mechanical energy: is the sumof potential energy and kinetic energy. It is the energy associated with the motion and position of an object. The law of conservation of mechanical energy states that in an isolated system that is onlysubject to conservative forces the mechanical energy is constant. If an object is moved in the opposite direction of a conservative net force, the potential energy will increase and if the speed not...