Friday, April 27, 2012

How electricity: which is an electric field

In the 18th century, thanks to research of Coulomb, could be established that electric charges interact at distance, as well as the mass against gravitational forces. I.e., that a mass or load might inexplicably, without any mediator to notice another in their environments.

 This idea was uncomfortable with physicists, even to the own Newton. Faraday proposed an alternative interpretation of very useful, based on the idea of field: space surrounding an electric charge is affected by its presence, since it modifies its characteristics.

In his attempt to represent him, Faraday described as invisible tentacles that are moving from the load. In this way, from the moment in which a body takes charge, this information or novelty is stretching in your environment quickly, indeed to the speed of light, and can eventually reach another load.
As it is true to speak of the interaction between a load and another, it is possible to also describe the same incident from the interaction of a cargo area that is.

To electric field can represent it with lines, by Convention, out of the positive charges and entering the negative charges. They indicate the direction of the field at every location, i.e. the direction of the electric force which would experience a timely and positive, load called burden of proof, if it is placed at each position in the field.

The number of lines is proportional to the intensity of the field, IE where the lines are very close, the field is large and where they are separated, the field is small.

Despite the many similarities between the actions electric and gravitational, should be clarified a difference: the gravitational field is always inlet to its source (a mass) while the electric field can be incoming or outgoing on the load that is generated, there are two different kinds of load.

View electric field requires some care, although it is possible to do it with some simple experiences. The simplest is to observe the direction of the hair covering the forearm when, for example,
We are approaching a bowed plastic rule.

Is also possible to obtain a representation at the level of the electric field linesor in the following manner: put a mixture of oil for the body and very small pieces of human hair, no more than 2 mm of
long, on a flat glass, such as a microscope slide. If we bring a charged object, observe that the orientation of the pieces of hair will follow the electric fieldlines.

Representation of electric fields created by positive and negative point charges.