Whoever chose electrical engineering as their main occupation, is very well known to some of the basic properties of electric current and its accompanying magnetic fields.One of the most important of them - it's right-hand rule.On the one hand it is difficult to name the rule by law.A more correct to say that this is one of the fundamental properties of electromagnetism.
As a rule of thumb?Determining while there, but for a more complete understanding of it is worth remembering the basics of electricity.As already known from school physics course, the electric current is the motion of elementary particles carrying an electric charge on any conductive material.Usually, it is compared with the interatomic displacement of valence electrons, which are due to external influence (for example, magnetic pulse) receive a portion of energy sufficient to escape its steady orbit in the atom.A thought experiment.For this we need the load, the source of EMF and the conductor (wire) that connects all of the elements in a single closed circuit.
Source Explorer creates directional movement of elementary particles.At the same time in the 19th century it was noticed that around such a conductor, a magnetic field that rotates in one direction or another.The rule of thumb is just to determine the direction of rotation.The spatial configuration of the field is a kind of tube, which is located in the center of the conductor.One would think: what's the difference, the behavior is generated by the magnetic field!But even Ampere noticed that two conductors with current influence each other with their magnetic fields, pushing or being attracted to each other, depending on the direction of rotation of their fields.In the future, based on a series of experiments conducted by Ampere formulated and justified its interaction law (by the way, it is the basis of electric motors).Obviously, not knowing a rule of thumb, to understand the processes is very difficult.
In our example, the current direction is known - from "+" to "-".Knowledge of trends makes it easy to use the right-hand rule.Mentally begin to twist gimlet with a standard right-hand thread in the conductor (along it) so that the resulting translational movement has been aligned with the direction of current flow.In this case, the rotation of the handle coincides with the rotation of the magnetic field.You can use another example: the usual screw-bolt (bolt, screw).
This rule can be used a little differently (although the main meaning is the same) if mentally embrace the right hand conductor with a current so that the four bent fingers pointed to the direction in which the rotating field, then bent the thumb will point in the direction of the currentflowing through the conductor.Accordingly, the opposite is true: knowing the current direction, "wrapped around" the wire, you can see the direction of rotation vector generated by the magnetic field.This rule is widely used in the calculation of inductors, which depending upon the direction of turns possible to influence the current flow (creating, if necessary, counter).
Act thumb allows us to formulate a consequence, if the right hand post so that the line of tension generated by the magnetic field enters into it, and four straightened finger pointed to a known direction of motion of charged particles in a conductor is bent at an angle of 90 degrees highthe finger will point to the direction of the vector force exerted on the conductor biasing effects.By the way, this force creates any motor shaft torque.
As you can see, how to use the above rules a lot, so the main "difficulty" lies in the selection of each person it is clear to him.
