We express that what are the examples of electrical insulators with its uses and definition. In addition: Nature of Insulators
Definition of Electrical Insulators
An Insulating Material is any substance that is almost totally incapable of conducting an electric current , and is therefore used to block its passage.
Insulators and conductors
Some materials allow the passage of electric current better, in general metals; these materials are known as Conductors . These materials are electrified on their entire surface, even if only a point of it is rubbed.
Not only are metals conductors of electricity; Substances such as Water (under certain conditions), solutions of acids, bases and salts dissolved in Water, and the human body are also conductors of electricity.
The air conducts electricity but not as good a conductor as metals; this ability to conduct electricity can make it very dangerous . For example, in a thunderstorm, charges can move from the clouds to the ground due to the ability of moist air to conduct electricity.
Materials that prevent the passage of electric current are called Insulators or Dielectrics ; these materials are only electrified at the points where they make contact with a charged body , or in the rubbed part, that is, they maintain the electric charges in the part where they are formed or received, without transmitting them to the rest of the material.
Some examples of insulating materials are: Wood , Glass , Rubber , Resins and Plastics , Porcelain , Silk , Mica and Paper .
Nature of Insulators
Substances such as Wood and Glass and the above mentioned do not conduct electricity like metals do. In essence, the electrical conductivity of a solid depends on the spacing and the state of occupation of the energy bands.
In the case of Magnesium and other metals, the valence bands are adjacent to the conduction bands and therefore these metals easily act as conductors. This means that the valence electrons are very close to the region in which they are capable of displacing electrical energy.
On the other hand, in wood and glass the space between the valence bands and the conduction bands is much greater than in metal. As a consequence, much more energy is required to excite an electron into the conduction band. The absence of this energy prevents the free mobility of the electrons. Therefore, glass and wood are insulators, unable to conduct electricity.
Uses of electrical insulators
Electrical insulators such as Plastic are dedicated to the manufacture of electrical cables, which are copper wires wrapped in a plastic that prevents the metal surfaces from making contact with the outside.
In this way, the optimal conduction of the electric current from the source towards the apparatus that will be put into operation is also favored.
Electrical insulators are used to confine an electric field, so that it does not leak and can be directed to another point with a certain electric potential. It will then be the potential difference between that point and the functional device, which will drive the electric current.
Examples of electrical insulators