Question

Explain the principle of a device that can build up high voltages of the order of a few million volts.

Answer 1

Van de Graff generator is the device used for building up high potential differences of the order of a few million volts.

Such high potential differences are used to accelerate charged particles such as electrons, protons, ions, etc.

It is based on the principle that charge given to a hollow conductor is transferred to outer surface and is distributed uniformly over it.