Abstract

Faraday's law is that when the flux in the conductor loop changes, it produces electromotive force in the conductor loop, and obeys to contour integral law dU = - d(Phi)/dt dl, Maxwell Curl Theory is that when the magnetic intensity of a certain point in ether space changes, there produces electric field at that point in ether space, which is the field mutual production theory of ?electric field produces magnetic field and magnetic field produces electric field? in the free space which everybody is familiar with, and it obeys differential law curl E = -dB/dt; Lorentz magnetic force is that when metal electrons cut magnetic lines, metal electrons forced by F = qv x B move along the conductor to form inductive current, in fact, it doesn't matter whether coil moves or magnet moves, only if there exists relative motion between magnetic field and conductor, metal electrons must cut magnetic lines, which is, ?coil stills while magnet moves to the left? and ?magnet stills while coil moves to the right? these two situations are the same, which both belong to metal electrons having cut magnetic lines. According to the difference among the above three theories, this article introduces two experimental methods, the first one is the experimental method to distinguish Lorentz magnetic force and Faraday's Law, the second one is the experimental method to distinguish Lorentz magnetic force and Maxwell field mutual production theory, it can obtain the conclusion that ?general Lorentz magnetic force is the physical essence of all electromagnetic inductions? through analysis.