Wu Shaodong
(Liujing branch of Guangxi Hengxian post office, Liujing, 530313; 26 years old, male)
abstract This paper puts forward the principle of "the same direction magnetic field repels each other, the opposite magnetic field attracts each other" and introduces its application. It holds that the formulation of "the same name magnetic pole repels each other, the different name magnetic pole attracts each other" is not appropriate, and puts forward the modification suggestions for "the magnetic pole". Key word magnetic field;magnetic pole;magnetic force Classification number O 482.51
Magnetic field is the medium of interaction of magnetic source, and the interaction effect of magnetic source is directly related to the direction of magnetic field. The principle of "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field" proposed in this paper is a more fundamental electromagnetic principle that can be used to judge and analyze the interaction phenomenon between magnetic fields According to the principle of field mutual attraction, a series of judgment methods such as Lenz's law, left-hand rule, right-hand rule, right-hand spiral rule, mutual exclusion of magnetic poles of the same name and mutual attraction of magnetic poles of different names can not be used.
We know that the theory is a view summed up from the limited practice, "the same name poles repel each other and the different name poles attract each other" is a simple and long-standing consensus, the scientific community has been lack of deep argument for it, this paper thinks that its formulation is not appropriate, and puts forward suggestions for the modification of "magnetic pole".
1 The same direction magnetic field repels each other and the opposite magnetic field attracts each other
We can judge according to the direction of the mutual "contact" of the magnetic field of the magnetic source, and analyze the interaction phenomenon between the magnetic sources, that is: "the same direction of the phase contact magnetic field repels each other, and the opposite direction attracts each other.
As shown in Figure 1, two magnets with different magnetic poles close to each other will attract each other due to the mutual "contact" of their magnetic fields, i.e. "opposite magnetic fields attract each other". And the opposite magnetic fields will be "spliced" due to mutual attraction (in line with the experimental facts and the view that the magnetic lines are not intersected, as shown in Figure 2), and the "spliced" magnetic fields will be blown up due to the same direction of the magnetic fields (as shown in Figure 2). Here, we can realize that the principle of "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field" can not only be used to judge the interaction effect between magnets, but also be a theoretical tool for us to describe the change, formation and shape of magnetic field.
The moving positive charge shown in Fig. 3 will deflect to the left due to the mutual reversal of the generated magnetic field and the left side of the entered magnetic field, and the mutual co direction of the right side. That is to say, the charge deflects to the left under the mutual action of the magnetic fields. Here, the principle of "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field" can not only be used to judge the force direction of the moving charge, but also reflect that the force received is a resultant force of mutual "attraction" and "repulsion" of the magnetic field.
As shown in Fig. 4, the magnet moves towards the ring coil, and tries to judge the induced current direction of the ring coil. According to the "principle of action and reaction" (Lenz's law is an expression of "principle of action and reaction" in magnetic field, when using the principle of "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field" to judge and analyze electromagnetic induction phenomenon, the more universal "principle of action and reaction" can be directly used, and the assistance of Lenz's law can not be used to understand electromagnetic Phenomenon) it can be seen that the induced magnetic field around the ring coil will obstruct the magnetic field movement of the magnet. According to the analysis of the principle of "mutual repulsion of the same direction magnetic field", the upper part of the induced magnetic field around the ring coil is counter clockwise, the lower part is clockwise, and then through the ampere rule (the direction of the right extended thumb is the current direction, and the curved one In addition, the direction indicated by the other four fingers is the direction of the magnetic field).
2 The magnetic poles of the same name may not repel each other, and the magnetic poles of different names may not attract each other
The two conclusions in the textbook are contradictory: "the same pole repels each other, the different pole attracts each other", "the same direction current attracts each other, and the reverse current repels each other". As shown in Figure 5, if the analysis is based on "the poles of the same name repel each other, and the poles of different names attract each other", then the relationship between point a, point B and point C on the electromagnet is mutual attraction, and the relationship between point B and point C is mutual exclusion. If the analysis is based on "the same direction current attracts each other and the reverse current repels each other", then it is: point a on the electromagnet is mutually exclusive with point B and point C, and point B and point C are mutually attractive. Similarly, for a natural magnet placed as shown in Figure 5, if we analyze it according to "mutual attraction of the same direction current and mutual repulsion of the reverse current" (judged according to "molecular current hypothesis" for "current direction") or "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field", we will think that the mutual repulsion relationship exists between the upper side and the lower side of the magnet, while the upper side and the lower side respectively There is a mutual attraction relationship between them, and there is also a mutual attraction relationship between them on the lower side (according to the analysis of "molecular flow hypothesis", the outside part of the side of the magnet is totally neutral), which is also the understanding of "the two poles of the magnet are inseparable". The reason why the two magnets shown in Fig. 1 show "attraction of different magnetic poles" is that they "attract each other on the same side", while their diagonal sides are mutually exclusive.
If the two magnets shown in Figure 6 are analyzed according to the principle of "the poles of the same name repel each other", they should repel each other, but in fact they are attracted to each other. This phenomenon can be analyzed according to "mutual attraction of reverse magnetic field": because the magnetic field of two magnets is "in contact" with each other, the two magnets will be attracted together under the mutual attraction, splicing and contraction of the magnetic field.
In the case shown in Figure 7, the two magnets will show mutual repulsion, but if we understand this phenomenon by "mutual repulsion of magnetic ends of the same name", it is not appropriate. Because a and B on the "magnetic end" are still attractive to each other, the reason why they are repulsive to each other is that the repulsive force between their upper and lower magnetic fields and the "splicing" magnetic field in the middle is relatively large.
As shown in Figure 8, when the small magnetic disc q is close to the cylindrical magnet K placed on the flat table along the dotted line L, in what direction will k roll? If the analysis is based on "the poles of the same name repel each other, and the poles of different names attract each other", then the N-pole of Q has a repulsive force that points to the top left of the N-pole of K, and K should roll to the left. If the analysis is based on "the same direction magnetic field repels each other, and the reverse magnetic field attracts each other", it is: the upper magnetic field of Q has a repulsive force to the right magnetic field of K, which points to the upper right (or the upper right, near the upper right); the left magnetic field of K has a direction which points to the lower right, and K should roll to the right. Experiments show that when q is about (specifically related to two magnets) to K in the range between dotted line I and j, K will roll to the right, "the same name poles repel each other, and the different name poles attract each other" is contradictory to the experimental facts; when q is about (specifically related to two magnets) to K in the left of dotted line I or the right of dotted line j, K will be forced to roll to the left, "the poles of the same name repel each other, The expression of "attraction of different magnetic poles" coincides with the experimental facts at this time, and the principle of "mutual repulsion of the same direction magnetic field and mutual attraction of the reverse magnetic field" can explain the experimental facts very well. If the magnet K and Q with strong magnetic force are put on the hand for experiments, the "attraction" and "repulsion" relationship of the force of the above-mentioned magnetic phenomena can be obviously felt.
As shown in Figure 9, if the analysis is based on "the poles of the same name repel each other, and the poles of the different names attract each other", then it is: the N poles of the magnet repel each other with the N poles of the magnetic needle, and the S poles of the magnetic needle attract each other, so the magnetic needle will deflect 90 clockwise. If the analysis is based on "the same direction magnetic field repels each other, and the reverse magnetic field attracts each other", it is: the left magnetic field of the magnet and the lower magnetic field of the magnetic needle will attract each other and "splice" each other due to the reverse reason, and the "splice" of the magnetic field makes the right magnetic field of the magnet and the upper magnetic field of the magnetic needle have "contact" with each other. Finally, the upper magnetic field of the magnetic needle and the right magnetic field of the magnet Under the main action of mutual attraction, splicing and contraction of the side magnetic field, the clockwise deflection is 90 °. In this paper, we can realize that the judgment of "the same name poles repel each other, and the different name poles attract each other" in some cases is generally consistent with the experimental results, but the analysis process is still inappropriate.
If we straighten the electrified ring coil, its two magnetic poles will not exist. The magnetic pole is obviously a physical phenomenon surrounded by the "special flow direction" of the magnetic field. For example, the "special flow direction" of the air forms a tornado, not a tornado produces air, which is different from the logic of "electric field generated by charge". Because of the existence of free charge, we can deduce free magnetic field The idea of the existence of charge (monopole) is worth exploring. The author thinks that the formulation of magnetic pole is easy to be understood as "the magnetic pole is a kind of substance". In order to make it easier for people to understand the electromagnetic phenomenon accurately, it may be more reasonable to call the two magnetic poles of a magnet "magnetic notch" or other names. The direction of "magnetic notch" can be marked on both ends of the magnet with "·" and "×". The magnetic field line (now called "magnetic induction line" in textbooks) does not really exist In, it is an image expression of magnetic field. The magnetic field line can be considered to be renamed "magnetic state expression line (magnetic state line)".
(Responsible editor Tang Hanmin)
Journal of Guangxi University(Natural Science Edition)
Volume 24 supplement
June 1999
Date of receipt:1999-03-20