Not too sure... Is the answer something about non-conductors holding the charge at the surface but charges in conductors flow throughout the material. But I thought that all the spheres will become negatively charged upon contact with the negatively charged roller.
HELP. THANKS
The figure below shows an electrostatic method of separating conducting and non-conducting spheres
Why do the conducting spheres fall off from the roller while the non-conducting spheres have to be scrapped off?
Thanks for the help.
Cheers,
Winston