Definition of Electric Field, Permittivity and their Formulas.
Before we define, electric filed we need explanation of several other important concepts. We will then electric charge. As already mentioned, the smallest carrier of electric charge is an electron. Since it is assumed that a negative charge is simple and intuitive definition of the loads of the bodies (particles) that is reduced to overflow or underflow of body electrons.
The excess of electrons causes the body is negatively charged, and their insufficiency is so called as positively charged. The value of filed strength can be concluded on the basis of the force of their mutual interaction. The strength of this can be calculated from Coulomb's law:
The excess of electrons causes the body is negatively charged, and their insufficiency is so called as positively charged. The value of filed strength can be concluded on the basis of the force of their mutual interaction. The strength of this can be calculated from Coulomb's law:
where:
q 1 and q 2 - the value of goods
ε - the so-called. The absolute dielectric material, wherein the load provided
r - distance between charges
4 Pi- So-called. rationalization factor, which is the result of the findings of the SI
It requires further clarification permittivity ε. In the vacuum (or air in practice) the absolute permittivity is:
while the expression:
It called the relative permittivity. It indicates how many times less the force of the interaction between the charges in the resort is as compered to in a vacuum.
As you can see, the force calculated from Coulomb's law is directly proportional to the value of charges and inversely proportional to the square of the distance between them. Just be aware that your body with the same charges repel, and opposite charges.
The pattern does not explain, however, why this is happening. Intuition suggests that the essence of each electric charge is surrounding electric field . It is invisible, but its existence can be confirmed experimentally and that it induces interaction between charges. Each electric field characterized by a vector. The intensity of the electric field E is called the ratio of the force, which acts on the field . In other words, at any point charge q placed in an electric field intensity E, the field interacts with the force:
f = q * E
This force is independent of the cargo which comes from the field. I remind you that the unit of electric field strength is volts per meter (V / m).
In order to create a geometric interpretation of the electric field was introduced the concept of electric field lines (lines of force). These are lines in which each point of the field vector E is oriented tangentially to the line. This explains the figure below.
