The phenomenon of induced electromotive force due to the change of magnetic flux (when a part of the conductor of a closed circuit cuts the magnetic field lines, a current will be generated in the conductor, which is called electromagnetic induction.

Problem description:

Electromagnetic induction is caused by the change of magnetic flux, but why does the change of magnetic flux produce electromagnetic induction?

Reference answer:

The essence of electromagnetic induction can be traced back to Maxwell's electromagnetic field theory: the changing magnetic field produces an electric field in the surrounding space. When the conductor is in this electric field, the free electrons in the conductor move directionally under the action of electric field force to produce current, that is, induced current; If it is not a closed loop, the directional movement of free electrons in the conductor causes the accumulation of negative charges at both ends of the disconnection point, resulting in potential difference induced electromotive force.