Electromagnetic Induction and Magnetic Induction

Electromagnetic induction and magnetic induction are two very important concepts in electromagnetic field theory. The applications of these two concepts are numerous. These theories are so important even the electricity would not be available without them. This article will discuss the difference between electromagnetic induction and magnetic induction.

What is Magnetic Induction?

Magnetic induction is the process of magnetization of materials in an external magnetic field. Materials can be categorized to several categories according to their magnetic properties. Paramagnetic materials, Diamagnetic materials and Ferromagnetic materials are to name a few. There are also some lesser common types such as anti-ferromagnetic materials and ferrimagnetic materials. Diamagnetism is shown in atoms with only paired electrons. The total spin of these atoms is zero. The magnetic properties arise only due to the orbital motion of electrons. When a diamagnetic material is placed in an external magnetic field, it will produce a very weak magnetic field antiparallel to the external field. Paramagnetic materials have atoms with unpaired electrons. The electronic spin of these unpaired electrons acts as small magnet, which is very stronger than the magnets created by the electron orbital motion. When placed in an external magnetic field, these small magnets align with the field to produce a magnetic field, which is parallel to the external field. Ferromagnetic materials are also paramagnetic materials with zones of magnetic dipoles in one direction even prior to the external magnetic field is applied. When the external field is applied, these magnetic zones will align themselves parallel to the field so that they would make the field stronger. Ferromagnetism is left in the material even after the external field is removed, but paramagnetism and diamagnetism vanishes as soon as the external field is removed

What is Electromagnetic Induction?

Electromagnetic induction is the effect of current flowing through a conductor, which is moving through a magnetic field. The Faraday’s law is the most important law regarding this effect. He stated that electromotive force produced around a closed path is proportional to the rate of change of the magnetic flux through any surface bounded by that path. If the closed path is a loop on a plane, the rate of magnetic flux change over the area of the loop is proportional to the electromotive force generated in the loop. However, this loop is not a conservative field now; therefore, common electrical laws such as Kirchhoff’s law are not applicable in this system. It must be noted that a steady magnetic field across the surface would not create an electromotive force. The magnetic field must vary in order to create the electromotive force. This theory is the main concept behind electricity generation. Almost all of the electricity, except from the solar cells, is generated using this mechanism.

What is the difference between electromagnetic and magnetic induction? • Magnetic induction may or may not produce a permanent magnet. Electromagnetic induction produces a current so that the generated current opposes the change in the magnetic field. • Magnetic induction only uses magnets and magnetic material, but electromagnetic induction uses magnets and circuits.