Physics:Nonelectrostatic electric fields

From HandWiki

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]

Origin

To understand the origin, consider a wire loop, placed in magnetic field. According to Faraday's law of induction, 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 produces 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 given region magnetic field changes with time, an electric field is induced in this region, which causes motion of electrons in the loop. But, an electric field can be there even if we don't place a loop. So, the complete discussion will be that if the magnetic field is changing, the electric field will appear, circulating the changing magnetic field.