The angular inertia of the flywheel shit. $L$ is inductance.
$$L = \frac{\Phi(i)}{i}$$
Inductance remains constant for a given [[inductor]] so long as its geometry doesn't change due to $B(i) \propto i$
$$L = \frac{\Phi(i)}{i}$$
$$L = \frac{\Phi(i)}{i}=\frac{B(i)\cdot A}{i}$ = \frac{(C \cdot i) \cdot A}{i} = CA$$
Accordingly, if you have a [[Solenoid]] with $N$ turns and $\Phi$ is the flux through a single turn.
$$L = N\frac{\Phi(i)}{i}$$