Conductors and Insulators
Conductors and Insulators
Some materials allow electrons to move relatively freely through them (e.g. most metals, the human body). These materials are called conductors.
Other materials do not allow the charge carriers, the electrons, to move through them (e.g. plastic, glass). The electrons are bound to the atoms in the material. These materials are called non-conductors or insulators.
Tip:
The effect of the shape on the charge distribution is the reason that we only consider identical conductors for the sharing of charge.
If an excess of charge is placed on an insulator, it will stay where it is put and there will be a concentration of charge in that area of the object. However, if an excess of charge is placed on a conductor, the like charges will repel each other and spread out over the outside surface of the object. When two conductors are made to touch, the total charge on them is shared between the two. If the two conductors are identical, then each conductor will be left with half of the total net charge.
This lesson is part of:
Electric Charges and Fields