text: In electrodynamics, the Maxwell-Faraday law of induction can be stated in two equivalent forms: that the curl of the electric field is equal to the negative rate of change of the magnetic field,
  or that the circulation of the electric field around a loop is equal to the negative rate of change of the magnetic field flux through any surface spanned by the loop, by Stokes' theorem
  Circulation of a static magnetic field is, by Ampère's law, proportional to the total current enclosed by the loop
  For systems with electric fields that change over time, the law must be modified to include a term known as Maxwell's correction.