What is vandigraph generater?

A Van de Graaff generator is an electrostatic machine that uses a moving belt to accumulate electric charge on a metal dome, creating high voltages. It operates on the principle of electrostatic induction, allowing it to generate voltages up to several million volts. Commonly used in physics demonstrations and experiments, it illustrates concepts such as electric fields and discharge phenomena. The device is named after physicist Robert J. Van de Graaff, who invented it in the 1930s.