CBSE Class 12-science Answered

The Van de Graff generator is an electrostatic generator capable of producing enormously large static electric potential. There is a belt which runs over two metal pulleys. One of the pulleys is surrounded by a hollow metal sphere. Two electrodes with sharp metal points are placed near the bottom of the lower pulley, inside the sphere. As the belt passes in front of the lower comb, it receives negative charge that escapes from its points due to the influence of the electric field around the lower pulley, that ionizes the air at the points. As the belt touched the upper pulley, it transfers some negative charge and left with negative charge, the negative charge on the belt generates enough electric field to ionize the air near the upper sphere.