Here is an excellent starter with nothing more than algebra required:
Don't blindly trust that presentation! It contains serious errors!
For example, it claims that when you take an air-core inductor and insert an iron core, the inductance will rise in direct proportion to the core's permeability. This is NOT TRUE!
To actually get such an inductance increase proportional to core permeability, you would need a liquid core of infinite size. Imagine a tank, much larger than the coil, filled with some liquid that has a certain permeability, and then immerse your coil in it. That will give you the proportional inductance increase the author claims.
But not a normal, solid core. Such a core ALWAYS has a smaller cross sectional area than the air that surrounded the original coil, and for that reason the inductance increase produced by inserting a core is always less than its permeability!
Manfred
