According to Faraday's law a changing flux through a loop will create an Electric-field curling around that loop. And if the loop is a conducting wire the current looping will create an opposing magnetic field as below(Lenz):

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But what if there is no wire and no current but just the circulating/looping Electric-filed around an imaginary loop? Would that Electric field generate an opposing magnetic filed as well?


1 Answer 1


Maxwell's correction to Ampere's Law states:

$$\nabla\times\mathbf{B}=\mu_0\mathbf{J}+\mu_0\epsilon_0\frac{\partial\mathbf{E}}{\partial t}$$

Even when $\mathbf{J}=0$, we still could have nonzero $\frac{\partial\mathbf{E}}{\partial t}$, which generates a magnetic field. Without this correction, propagation of electromagnetic waves would be impossible.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – ACuriousMind
    Commented Jul 13, 2017 at 10:27
  • $\begingroup$ But would this magnetic field you mention, be opposing to magnet's field? like the magnetic field in original faraday experiment opposes motion magnet....because if it is really so then moving a magnet in just air will produce opposing force which is impossible $\endgroup$
    Commented Mar 29 at 5:35
  • $\begingroup$ @Amit Rai, see answer here: physics.stackexchange.com/a/808189/283846 There will indeed be an opposing force, the radiative reaction. $\endgroup$ Commented Mar 29 at 9:27

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