One of the most important physical characteristics of both natural and artificial human environment is the magnetic field.It is a form of existence of the electromagnetic field.The main distinguishing feature of this form is that the magnetic field acts only on those particles and bodies, which, on the one hand, are in continuous movement, and on the other - comprise a specific electrical charge.
Another of physics course known that for generating a magnetic field necessary to guide current and alternating electric fields.The most important characteristics of this field are the vector of magnetic induction and magnetic intensity.
The magnetic field is one of the vector variables studied in physics, which is the sum of the difference vector of electromagnetic induction, and the magnetization vector.Since the magnetic intensity vector is a quantity, then its unit of measurement in the conventional and most common SI is considered amperes per meter.To receive the electromagnetic field and the value of 1 / m, it is necessary that in an extended rectilinear wire with a maximum cross-sectional diameter small electric current flows 2π power amp.In this case all points formed by this current magnetic field at a distance of 1 meter, and the electromagnetic field intensity is equal to 1 A / m.
magnetic field intensity, or in other words, the number of lines of force of the field can be estimated.In particular, to determine the direction of these lines, you can use a well-known rule of thumb all.That's right - one of the cornerstones of the entire electrical engineering.It states that in the event that the overall thrust of the motion of thumb is completely identical to the direction of the electric current in a particular conductor, the direction of rotation of the thumb is identical to the direction of magnetic field lines.
guided by the rule, it is easy to prove that the magnetic lines that arise in the coil windings are directed to the same side.From this we can conclude that the intensity of the magnetic field inside the coil will be much stronger than the tension created by one turn.It is connected also with the fact that the lines of force of adjacent turns are parallel to each other but in different directions, hence, the magnetic field between them will decrease steadily.
Naturally, the magnetic field of each coil is directly proportional to the magnitude of the current that passes through its coils.In addition, the magnetic field depends on how closely these windings arranged in relation to each other.Empirically, it is proved that in the two coils in which electric current flows the same strength, and the number of turns completely coincide, the magnetic field is stronger than the one where the coil has a smaller axial length, i.e. its coils are much closer to each other.
very important characteristic of a magnetic field ampere-turns is a numerical value that can be calculated by multiplying the number of turns in the coil on the strength of the current flowing in them.From the value of ampere-turns will depend on the magnetomotive force.Based on this concept, it is easy to prove, that the magnetic field investigated coil is directly proportional to the number of ampere-turns, depending on the axial length of the unit.In other words, the electromagnetic field strength is higher, the greater the magnitude of the magnetomotive force generated in the test coil.
addition artificially generated magnetic fields, there is a natural magnetic field of the Earth, which is formed mainly in the outer shell of the nucleus.Main characteristics of this field, including tensions vary both in time and in space, but all the basic laws characteristic artificially created fields, and operate in the geomagnetic field.
