Question

Explore and answer :

Swetha rubbed a plastic ruler on her hair, then took the ruler close to bits ofpaper. The bits of paper were attracted to the ruler. But when Geetha tried the same with a metal ruler, the bits of paper did not stick to it. Could you explain the reason ?

Answer 1

A plastic is an insulator which gets electrically charges when rubbed on hair. It therefore attracts small bits of paper because paper gets polarized din the presence of charged plastic ruler resulting in a net force of attraction.But whereas metal is a conductor, so a metal ruler does not get electrically charged by rubbing it on hair. So, it does not attract bits of paper.