What is a magnetic field? How were they formed?

Question

What is a magnetic field?  How were they formed?

Piper Hoffman · Accepted Answer

I am not sure that my answer will satisfy you but...

A magnetic field is a region of space where, in every point, is present a magnetic force odf the type: #vecF=q(vecvxxvecB)# where #vecB# is our magnetic field (vector). Here you can see a similarity with Electric Field where you have: #vecF=qvecE# The velocity term is present in the first, which is the difference! We can resume all saying that: A charge produces around itself an Electric Field #vecE#; if it moves it will also produce a Magnetic Field #vecB#. Both fields will be sensed by the presence of a force. We can summarize mathematically by writing (for a charge #q#): #vecF=q(vecE+vecvxxvecB)# If the charge is at rest it is ok you get only a E field...if it also moves we add the Magnetic one! In essence, a magnetic field forms whenever there is a moving charge. Some examples of this include: 1) the area surrounding an electrical wire; 2) a magnetic material, where the electrons are "moving" within the atoms; and 3) the area inside and surrounding a solenoid that is carrying current (such as in a transformer). I hope it's useful.

Henry Asbill · Answer

undefined A magnetic field is created by moving electric charges, such as currents flowing through conductors or electrons moving within atoms, and is defined as an area where magnetic forces are applied to charged particles.