Electrostatic field and single charge

In society, there is a stereotype that only matter can be considered as matter that not only exists, but also visibly. This belief is only partly true. One of the vivid examples of invisible matter is the electrostatic field. Magnetic and electric fields are a special kind of it. It is easy enough to verify this if we consider the electrostatic field and its characteristics.

Back in 1785, S. Coulomb discovered and justified the law on the strength of the interaction of two point bodies with electric charges. However, it remained unclear how the impact was transmitted. A number of experiments were carried out, in particular, when the charges were located in a vacuum. The law was observed. This allowed us to assume that the usual intermediate medium is not needed to transfer power. Later, Maxwell (based on Faraday's works) discovered an electrostatic field in a vacuum. It turned out that the field always exists around charges, regardless of the type of environment, and ensures their interaction.

Since the field is material, it "obeys" Einstein's formulas and propagates with the speed of light. The electrostatic field has received its name due to the fact that it is characteristic for stationary charges ("static" - rest, balance). The power found by the Pendant is called electrical. It describes the intensity with which the field acts on the charge introduced into it.

One of the characteristics that an electrostatic field possesses is its tension. Indicates the degree of interaction of point charges. To study, use the so-called test charge, the introduction of which in the field does not distort the latter. Usually it is assumed to be 1.6 * 10 to the power of -19 pendant. If the intensity is denoted by the letter "E", then we get:

E = F / Q,

Where F is the force acting on the unit charge Q (for example, test). The use of the Coulomb law for calculations requires taking into account the coefficient of dielectric permittivity of the medium.

The electrostatic field affects any number of charges, and a complex system of interactions arises. The tension of the system can be considered from the point of view of superposition, so the total effect of the N-number of charges is a vector sum of all the field strengths. By the way, the notion of the "line of tension" (the term known from the school course of physics) arose from Faraday, who schematically depicted the field lines, at each arbitrary point coinciding with the vectors of the electrostatic field intensity. Accordingly, the more such lines, the more intense the force. Unlike electromagnetic fields, lines of tension are not closed in electrostatics. It is also worth noting that in metals (and other conductive materials), the field strength is absent due to the counter-directed action of the field of free charge carriers in the crystal lattice structure. In fact, the forces quickly equalize, there is no current, and lines of tension in such a conductor can not penetrate.

In addition to vector quantities, the field can be described by the scalar values taken in each (ideal case) point. In electrostatics, these values characterize the field potential. We can say that it corresponds to the value of the potential energy for a unit positive charge at any given point in the field. Accordingly, the unit of measurement is Volt. It is determined by the ratio of the potential energy of the charge Q-test to its value, that is, W / Q-test.

The potential itself is equal to the work done by the forces of the electrostatic field, moving the charge from one point to another, infinitely remote.