Van de Graaff Generator

This is one of the most wonderful inventions man has ever made; its sheer simple operation fascinates the physicist and the laymen alike. Its uses, despite being a simple machine, speak volumes:
Nowadays, particle accelerators in nuclear laboratories use them extensively to get the high voltages they need.



The blue pointer at the bottom, that is connected to a very high positive voltage, generate positive ions. They in turn are deposited on the moving belt. The belt carries them around the interior of the green dome  that results in the induction of negative charges inside the dome and a similar positive charge outside.

The induced negative charges move along the brown rod and neutralize some of the positive charges on the belt. That makes it possible for belt to carry more and more positive charges, as it moves on, towards the top. However, the induced positive charge outside the dome is increasing rapidly and so is its potential, which can reach in excess of 107 Volts. This potential is widely used for commercial purposes.

Please answer the following questions.

    1) Discuss the significance of the pointed objects in the Van De Graff Generator. 2) Compare the Van De Graff generator and an electrical generator.
    3) Discuss the role of electrostatic induction in the device
    4) To have a hair-raising experience with Van De Graff generator, you are supposed to stand on an insulating stand. Explain.