Principle: We know that the capacity of a uniformly charged hollow spherical conductors is C=4πε0R Obviously, for the capacity to be large the radius R should be large. Further at the pointed ends of a charged conductor, the surface density of charge (i.e., charge/area) is more as compared to any plane surface, therefore the electric field near the pointed ends of the conductor is stronger than at any other places. The working of the Van-de Graff generator is based on these facts. Uses: (i) To generate high voltage. (ii) To accelerate α particles, protons, and deuterons, etc in nuclear disintegration. (iii) Disadvantage: Due to its large size it is not convenient to carry it from one place to another.