Why inductance of the iron cored coil changes with Current?

Answer 1

When current flows through a conductor, a magnetic field is established in the space or the material around the conductor. If this current is changed as a function of time, the intensity of the magnetic field will also vary with time. According to Lenz's law, this changing field will induce voltage differences in the conductor which will tend to oppose the changing current.

Answer 2

Transformers artwork purely with AC contemporary the place the iron (laminated) center of the transformer is alternately magnetized reversing poles. The center responds to the contemporary of the huge-unfold coil (means source) as magnetic flux cycles and the coils of the secondary winding experience the cycling flux and bring alternating electric powered tension (voltage) interior the output wires able to installation secondary contemporary by way of a related load. The center contains iron atoms each and each of that's a tiny randomly orientated magnet. the huge-unfold winding alternately reverses the orientation of the tiny magnets that could keep greater means from the flux than ought to an empty (air) center, improving overall performance.