What role does electrostatics play in a xerox copying machine?

Explanation

A xerox copying machine is one of the many industrail applications of the forces of attraction and repulsion between charged bodies. Particles of black powder, called toner, stick to a tiny carrier bead of the machine on account of electrostatic forces. The negatively charged toner particles are attracted from carrier bead to a roating drum, where a positively charged image of document being copied has formed. A charged sheet of paper then attracts the loner particles from the drum to itself. They are then heat fused in placed to produced the photo copy.