We have discussed that magnetic flux is a contrived but measurable concept that has evolved in an attempt to describe the “flow” of a magnetic field. It is very important for magnet users to comprehend the basic features of magnetic flux in circuit designing. Wherein:

·There are a variety of electrical current nonconductors in the world known as dielectrics. The electric current can be well confined in conductors. But there is essentially not any magnetic flux nonconductor. That is, the magnetic flux can freely penetrate into and pass through any kind of static materials whatever they are solid, liquid, or gas. For this reason, flux leakage is always existed in any magnetic circuit.

·Flux lines will always follow the path of lowest reluctance, that is, of the least resistance.

·Flux lines always repel each other when they are anear. Thus, flux lines can never cross and they normally move in curved paths.

·Flux lines always perpendicularly enter and leave the pole faces of a ferromagnetic material, and, move parallelly to the other boundaries of a ferromagnetic material except for the pole faces. In circuit analysis, boundary that flux lines are parallel to is known as Dirichlet boundary, in honor of P. G. L. Dirichlet (1805-1859). While boundary that flux lines are perpendicular to is known as Neumann boundary, in honor of Karl Gottfried Neumann (1832-1925).

·Any ferromagnetic materials have a saturation characteristic to carry flux. When an increase of magnetizing field produces no increase in magnetic polarization of a ferromagnetic material, the material is called in magnetic Saturation State. When a ferromagnetic material approaches its magnetic saturation, flux lines will pass as readily through the air or other non-ferromagnetic materials as through the magnet.