1.h comes from Ampere's Law. Ampere did the current experiment and found that the "magnetic field" was the same at the same distance from the long straight conductor; At points with different distances, the strength of the "magnetic field" is inversely proportional to the distance. The so-called "magnetic field" here is obtained by mechanical means such as the torque of a small magnetic needle. In this way, through mechanical measurement and the existing definition of current intensity, a physical quantity H can be defined, which satisfies 2 * pi * r * h = i, and it is the Ampere Loop Law after popularization.

At this time, the permeability of vacuum μ0 is not needed, because the physical quantity H can be defined as long as the current I is known.

2.b the force from charged particles. For a particle with a certain speed and H magnetic field, you can measure the force on the particle by orbital measurement and Newton mechanics. You find that the force is proportional to the number of charges Q and the speed, and also proportional to H, but the force F is not directly equal to qvH, and it is still a factor: F = A * Q * V Ⅶ h, and A is just an undetermined factor and has not been given physical meaning.

The difference between H and B units is only because the units used in the initial study of mechanics are completely independent from those used in the study of charge and current, which leads to a unit conversion. H comes from I and B comes from F, so what we see is the relationship between "giving H" and "receiving B"

3. In electromagnetism, magnetic permeability is the degree of magnetization of linear response of material to external magnetic field. Magnetic permeability is usually expressed by the Greek letter μ. This form was created and used by oliver heaviside in September 1885.

In the international system of units, the unit of permeability is Henry per meter (h m-1) or Newton per ampere squared (n a-2). The constant value \mu_0 is the magnetic field constant or permeability of vacuum, which has a clear definition value [1] \mu_0 = 4π× 10? 7 N A？ 2。

4. Magnetic flux, with the symbol φ m, is a measure of the magnetic field (also called magnetic flux density) passing through a given surface. The international unit of magnetic flux is Weber.

The difference between the two is obvious.