The principle mentioned in the question refers to the ability of a Van de Graff generator to accumulate large amounts of charge on a conducting sphere. This device uses the concept of continuous charge transfer and electrostatic induction to accumulate and store high-voltage electric charge. Thus, the principle described corresponds to the Van de Graff generator, which operates by continuously transferring charge onto a large conducting sphere.
Final Answer: Van de Graff generator
If the input frequency is 50 Hz, the output frequency of a full wave rectifier is: