CONDUCTOR,INSULATOR AND SEMICONDUCTOR

CONDUCTORS

In some materials, electrons move easily from atom to atom. A conductor is a substance in which the electrons are mobile and that can conduct electricity.The term conductor is applied to any material that will support a generous flow of charge when a voltage source of limited magnitude is applied across its terminals.The best conductor at room temperature is pure elemental silver. Copper, aluminum, iron, steel etc are examples for conductors. In most electrical circuits and systems, copper or aluminum wire is used. Silver is impractical because of its high cost.

INSULATORS:

Some substances prevent electrical currents from flowing through it, those substance are known as insulators. An insulator is a material that offers a very low level of conductivity under pressure from an applied voltage source.Most gases are good electrical insulators. Glass, dry wood, paper, and plastics are other examples. Pure water is a good electrical insulator.

SEMICONDUCTORS:

In a semiconductor, electrons flow, but not as well as they do in a conductor. That is semi conductors are partial conductor of electricity. A semiconductor, therefore, is a material that has a conductivity level somewhere between the extremes of an insulator and a conductor. Semiconductors carry electrons almost as well as good electrical conductors like copper or aluminum; others are almost as bad as insulating materials.