Nonelectrostatic electric fields

Non electrostatic electric fields are very much like the electrostatic electric fields, except that their origin is based on electromagnetic induction i.e. time varying magnetic field through a given region of space induces non-electrostatic electric fields. The striking difference between the two kinds of fields is that we cannot associate electric potential with points in such an electric field and that the work done by the electric force in such a field is not zero over a closed loop.[1]

To understand the origin, let us consider a wire loop, placed in magnetic field. According to Faraday's law, if the magnetic flux is changed through the loop, an emf will be induced in this. The magnetic flux may be changed by changing the area of the loop or by changing the magnetic field. Why a changing magnetic field proudces current in the loop. The loop contains electrons, which don't feel magnetic field, but if the magnetic field changes, they feel it. It is customary to think that if in a region magnetic field changes with time, an electric field is induced in this, which causes motion of electrons in the loop. But, an electric field can be there even if we dont place a loop. So, the complete discussion will be that if the magnetic field will be changed, electric field will appear, circulating the changing magnetic field.