In my Last article Experiment to Explain Frictional Electricity and Concept of Charging by Induction, we saw how a charged balloon was attracting small metal piece and then we explained the mechanism behind the scene.
Now the question is what if I suspend a piece of non-conductor instead of metal?
…..ha ha ha, Let’s see what happens by performing the experiment. Make the same set up again and see what happens in this case. And you will see, Oh My God!, even, the piece of non-conductor is attracted. And this means that previous fact is true even for non-conductors, but what about the mechanism, as non-conductors do not have free electrons, our previous discussion about “concept of charging by Induction” doesn’t apply here. Then think, how non-conductors are attracted by charged bodies. Here is an explanation-
When a body is placed near a charged body basically it is placed in an electric field. So here the non-conductor is placed in an electric field that results in a restoration in the structure of every individual atom. There is a shift in electron cloud around nucleus. That disturbs symmetric distribution of electrons around nucleus. As a result center of positive charge and negative charge are now separated. So every atom now turns into an dipole.
These all dipoles align according to electric filed. Because of this alignment the face of non-conductor near to charged body gets oppositely charged and the opposite face gets equally similar charge.
Now consider the interaction of charged body with these two face which have equal but opposite charge but different distance. The charge closer to body ( which, being opposite, is attraction ) have stronger effect than the charge at far end. So overall effect results an attraction of non-conductor with charged body.
The key conclusion is even non-conductors are charged by induction, though mechanism of charging is different.