Using the power lines can not only show the direction of the magnetic field, but also to characterize the magnitude of his induction.
We agreed to carry out the lines of force so that after 1 cm² area, perpendicular to the induction vector at a certain point, held the number of lines equal to the induction field at this point.
In the place where the induction field will be greater, the field lines are thicker.Conversely, where the induction field is smaller and less power line.
Thus, the density of the magnetic field lines are judged on the value of its induction vector and the direction of the field lines - the direction of this vector.
Observation of magnetic spectra of direct current and coil shows that the removal of the magnetic field of the conductor is reduced, moreover, very quickly.
magnetic field with unequal induction at various points called inhomogeneous.Inhomogeneous field is a field of straight and circular current, the field outside the solenoid, the field of the permanent magnet, etc.
magnetic field of the same induction at all points is called a homogeneous field.Graphically homogeneous magnetic field is represented by lines of force that represent well spaced parallel lines.
example of a homogeneous field is a field, located inside a long solenoid and the field between the closely-spaced parallel flat pole pieces of the electromagnet.
product of the magnetic field penetrating the circuit on the circuit area is called magnetic flux of the magnetic induction or simply flux.
Determination gave him and studied the properties of the English physicist - Faraday.He discovered that this concept allows to consider more deeply the nature of a single magnetic and electric phenomena.
denote the magnetic flux by the letter F, the area of the circuit S and the angle between the direction of the vector of induction B and the normal n to the loop area α, we can write the following equation:
F = B S cos α.
magnetic flux - is a scalar quantity.
Since the density of the lines of force of any magnetic field is equal to its induction, the magnetic flux equal to the whole number of power lines that run through the loop.
with the field and changing magnetic flux which penetrates the circuit: the amplification of the field it increases, the weakening - is reduced.
The unit of magnetic flux in the SI system receives a stream that runs through an area of 1 m², located in a uniform magnetic field with an induction of 1 Wb / m and perpendicular to the vector of induction.This unit is called Weber:
1 Wb = 1 Wb / m² ˖ 1 m².
changes its magnetic flux generates an electric field having a closed field lines (vortex electric field).This field appears in Windows Explorer as an action of foreign forces.This phenomenon is known as the electromagnetic induction, and the electromotive force arising in this case - induced emf.
Furthermore, it should be noted that a magnetic flux makes it possible to characterize the overall whole magnet (or any other source of magnetic fields).Therefore, if the magnetic flux density allows to characterize its effect at any one point, the magnetic flux - entirely.That is, we can say that it is the second most important characteristic of a magnetic field.So, if the magnetic induction is acting as the power characteristics of the magnetic field, the magnetic flux - is its power characteristics.
Returning to the experience, we can also say that every turn of the coil can be imagined as a separately taken a vicious turn.The same circuit, through which will pass the magnetic flux of the magnetic induction.In this case, it will be celebrated the induction electric current.Thus, it is subjected to a magnetic flux generated in the closed electric field conductor.And then it is an electric field generates an electric current.
