Question

Why it is preferable to classify materials into good or poor conductors instead of classifying into conductors or insulators?

Answer 1

Every material is a conductor. For example, we cannot cal air as an insulator because it can also conduct electricity when there is a lot of force (lightning). Therefore, it is better to classify them as good conductors and bad conductors.

Good Conductor :These are the materials which offers very low resistance to the flow (or in path of) of electric Current.

In other words these materials have very low resistivity.

E.g of good Conductor :silver, copper, aluminum, gold etc.

Bad Conductor :These are the materials which offers very high resistance to the flow(or in path) of electric Current.

In other words these materials have very high resistivity.

E.g. :paper, Mica, glass, teflon.