Faraday’s Law of Induction states that a change in Magnetic Flux generates an EMF and Current. The current can either be from a normal electric field, or an induced electric field (this).
These fields are colloquially known as eddy currents. The term comes from eddy, which means a small vortex/whirlpool of water. Since the currents make tiny loops, the name stuck. Eddy currents are both a blessing and a curse.
An induced electric field is non-conservative, i.e. the total Work done in a closed loop is non-zero. Also, theses induced electric fields form loops, something that only normally happens
This induced electric fields occur without requiring a conductor!
It also allows Faraday’s Law to express in a different form.
In Motional EMF
In Static-Induced EMF
In non-moving conductor with a changing magnetic field, Faraday’s Law of Induction states there must be an Induced EMF, specifically, a Static-Induced EMF.
However, the this cannot be caused by the magnetic force, because the magnetic force only applies to moving charges:
In a static conductor, and hence
What happens is that a new, induced electric field is generated surrounding the loops, which allows the Static-Induced EMF and Induced Current to form, even though the magnetic field is zero.
This field is created in a manner such that it’s magnetic field opposes the external magnetic field. The direction can be given as the opposite of the Right Curl Rule.
This field is not caused due to charge, and hence is labelled a non-Coulomb field. Some key differences between this one and the standard Coulomb Field are:
| Coulomb Field | Non-Coulomb Field |
|---|---|
| Conservative | Non-conservative |
| = 0 in a loop | in a loop |
| Starts at positive charge and terminates at negative charges | Forms closed loops, similar to Magnetic Fields |
| Forms due to charges | Forms due to a varying magnetic field |
| Can be used to calculate Electrical Potential | Not a conservative force, cannot be used to obtain Electrical Potential |