Monday 28 March 2011

Types of materials

Conductors

Conductors are material that easily allow electrical current pass through them with very-less opposition. Almost all metals are conductors. When ever you cut an electric wire, you can see copper or some other metal at its core. It’s because these metals can easily conduct electricity. Silver can conduct electricity better than copper; copper can conduct electricity better than gold. We don't use them because they are tremendously Costly due to their scarcity. In cases where electrical circuit needs to be short, like in PC B's and in IC's, gold has been used. Gold is chosen over silver because it’s static and doesn't retort
And / or corrode as quickly as silver. Examples of conductors are copper, silver, gold, aluminum, steel etc.

Insulators

Insulators are that material that does not conduct electricity under normal conditions. For instance: air is an insulator. You don't get electrocuted when forthcoming a plug point since air is an insulator. In irregular situations, air behaves like a conductor. For example, during a thunderstorm, extremely high voltage creates lightning bolts, which jump from one cloud to another or to the ground. At these excessive conditions, air will act as a conductor. Examples of insulators are plastic, rubber, paper, wood etc. 

Semiconductor

Semiconductors are materials that act like both conductors and insulators. In certain condition a semiconductor acts like a conductor. For example charcoal and graphite which are allotrope of Carbon act as conductor. Whereas diamond which has a different crystal structure act as an insulator. The conductivity of semiconductors can be improved
By adding certain impurities to them this is called doping. The conductivity may improve by pumping energy into semiconductor crystal in the form of heat or light. Example of is silicon, germanium etc.

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