THE FIELDS OF MOVING CHARGES — Edward Purcell & David Morin
Physics — E&M · van-de-graaff-current
Problem
Van de Graaff current *
In a Van de Graaff electrostatic generator, a rubberized belt 0.3 m wide travels at a velocity of 20 m/s. The belt is given a surface charge at the lower roller, the surface charge density being high enough to cause a field of 106 V/m on each side of the belt. What is the current in milliamps?