Was talking to someone else about inductance and what affects it’s value so I’ll repost here:
If you’re interested in the literal math behind physics I always recommend you check out hyperphysics first
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indcur.html
There’s a lot here, but the important thing is the equations at the end, specifically which variables are in the numerator and denominator, which ones are constants, and which ones have exponents (which would make them nonlinear).
So Inductance is:
L = (u * N² * A) / l
u is the magnetic permeability of the core. If it’s air it’s constant. If it’s different grades of iron you can multiply the inductance simply by winding it around different stuff
N² is number of turns. You can see it’s exponential, so double the turns means 4 times the inductance
A is area. A wider coil linearly increases the Inductance
l is length, and it’s in the denominator. A shorter coil linearly increases the Inductance
As a result, a perfectly flat wide disc coil wound around a flat disc of ferrite would have a really high inductance. A straight wire is the exact opposite of that and has a very low Inductance.