Question

How electric current is produced when the a magnetic field is changed rapidly??

Answer 1

A changing magnetic field produces a changing magnetic flux. 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. The direction of the induced EMF is determined by the application of Lenz’s law whereas the EMF produced is calculated by Faraday’s law of induction .

Answer 2

The current carrying wire produces a magnetic field around it .given by bio-savart's law .the most general concept is that a moving charge creates a magnetic field in the region around it. A moving charge means that electric field changes with time