Field strength: essence and main characteristics

The electric field, according to elementary physical representations, is nothing but a special kind of material medium that arises around charged bodies and influences the organization of interaction between such bodies at a certain finite speed and in a strictly confined space.

It has long been proven that an electric field can occur in both motionless and stationary bodies. The main sign of the presence of this kind of matter is its effect on electric charges.

One of the main quantitative characteristics of the electric field is the concept of "field strength". In numerical terms, this term means the ratio of the force that acts on the test charge, directly to the quantitative expression of this charge.

E = F / q pr.

The fact that the charge is trial means that he himself does not take any part in the creation of this field, and his value is so small that it does not lead to any distortion of the initial data. The field strength is measured in V / m, which is conditionally equal to Н / Кл.

Famous English researcher M. Faraday introduced the scientific method of graphical representation of the electric field. In his opinion, this particular kind of matter in the drawing should be represented in the form of continuous lines. They subsequently became known as "lines of electric field strength", and their direction, proceeding from the basic physical laws, coincides with the direction of tension.

Power lines are necessary to show such qualitative characteristics of tension as density or density. In this case, the density of the lines of tension depends on their number per unit surface. The created picture of the lines of force makes it possible to determine the quantitative expression of the field strength in its individual sections, and also to find out how it changes.

The electric field of dielectrics has quite interesting properties. As is known, dielectrics are substances in which there are practically no free charged particles, therefore, as a consequence, they are not capable of conducting electric current. First of all, all gases, ceramics, porcelain, distilled water, mica, etc. should be classified as such substances.

In order to determine the field strength in a dielectric, it is necessary to pass through it an electric field. Under its action, bound charges in the dielectric begin to shift, but they can not leave the boundaries of their molecules. The direction of displacement implies that the positively charged are displaced along the direction of the electric field, and the negatively charged ones are opposite. As a result of these manipulations, a new electric field arises inside the dielectric, the direction of which is directly opposite to the external one. This internal field appreciably weakens the external, hence, the intensity of the latter falls.

The field strength is its most important quantitative characteristic, which is directly proportional to the strength with which this particular kind of matter acts on an external electric charge. In spite of the fact that it is impossible to see this value, it is possible to draw an idea of its density and directivity in space with the help of the drawing of force lines of tension.