Question

Why change in magnetic field produces a current

Answer 1

According to Lenz's Law , Lenz's law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux and to exert a mechanical force opposing the motion. Thus the changing magnetic field creates an EMF which in turn induces an electric current.

Magnetic force comes from singular magnetic mono-poles that are directly caused by moving (linear, orbital, oscillating, vibrational) mono-charges (singular electro-static charges with one type (+ or -) and a given charge strength or potential). Therefore, moving electro-static charges (especially relativistic impacted) cause magnetic fields.

Therefore a changing magnetic field indicates a changing electric field (pole type to charge type). For EMF this is an oscillating electric field in the photon velocity vector. You can measure this relationship as a change in electric current.