We know that the current-carrying conductor placed in a magnetic field, subjected to a force.Its direction depends on the direction of the field lines and the direction of the current, if the latter are known, the direction of the force can be determined by using the left-hand rule or right screw.
Let us now consider what determines the value of this force.Referring to the experience.
suspension to the left shoulder of the rocker lever scales linear conductor AB and place it between the poles N and S of the electromagnet so that it is perpendicular with respect to the magnetic field lines.Consistent with this guide will include an ammeter, and a resistor, through which current can be measured in this conductor.Balance the scales and lock the chain.Let the current in the conductor AB sent from B to A. The balance weights broken;to restore it, on the right have to put an extra bowl raznovesok whose weight is equal to the force exerted on the wire vertically downwards.We now change our current conductor;we note that with increasing current increases and the force that acts on the conductor.Changes will show us that the force with which the magnetic field acts on the conductor is directly proportional to the current flowing through it.
Does this force from the length of the conductor AB?To resolve this issue, we will take conductors of different lengths at the same current.Measurements show us that the force with which the magnetic field affects the current-carrying conductor, will be directly proportional to the length of the conductor located in a magnetic field.
Let F - the force that affects the current-carrying conductor placed in a magnetic field, l - the length of the conductor and I - current in it.
With the change of length l, and the current conductor it is changing, as we have seen, and the magnitude of the force F.
same force F ratio to the length of the conductor to the current I, and it is a constant, independent of the current in it;therefore, this ratio can characterize the magnetic field.
This quantity is called the magnetic induction or magnetic induction.
denote magnetic induction letter B. By definition, one can write:
in = F / (I · l).
The SI unit of magnetic induction field induction acts in which the conductor with a current of 1 A and 1 meter long subjected to a force 1 N. Name of this unit: 1 Nm / (amper˖metr) (abbreviated 1 N / (A˖m)).
show that 1 n / a (A˖m) = 1 (V˖sek) / m²:
1 N / (A˖m) = 1 (N˖m) / (A˖m²) = 1 J /(A˖m²) = 1 (V˖A˖sek) / (A˖m²) = 1 (V˖sek) / m².
Unit 1 volt-second is called the Weber (Wb).Therefore, 1 WB / m² or 1 Tesla (T) - a unit of magnetic induction.Whereas in the emu unit of measurement of magnetic induction - gauss (G):
1 T = 10⁴ gauss.
Magnetic induction - vector quantity.The direction of the induction vector at this point is aligned with the direction of magnetic field lines passing through this point.
The SI magnetic induction - power characteristics of the magnetic field, similar to the way the electric field intensity expresses power characteristic of the electric field.
Knowing the induction of the magnetic field, it is possible to calculate the force on the current-carrying conductor, according to the formula:
F = BI l.
In Windows Explorer, with the current charges are moving not just randomly in different directions, but also in a certain direction.Each of the charges to a magnetic force that is transmitted to the conductor.The sum of all forces from the chaotic motion is zero, and the sum of the forces directed motion called Ampere force.
In general, the magnitude of the force that affects the current-carrying conductor placed in a magnetic field is determined by the law of Ampere:
F = BI l sin α, where α - the angle between the direction of the current (I) and the magnetic field vector (B).
induction magnetic field is numerically equal to the force with which the magnetic field acts on a single element of the current, located perpendicular to the vector of induction.Magnetic induction depends on the properties of the medium.
