Define inductance, give its units and write factors on which its value depends.

(N/A) Inductance is the property of a coil by virtue of which it opposes any change in the current flowing through it. It is defined by the relation $N \Phi_{B} = L I$, where $L$ is the inductance.
The $SI$ unit of inductance is henry $(H)$.
Inductance depends on the following factors:
$(1)$ Number of turns $(N)$ in the coil.
$(2)$ Area of cross-section $(A)$ of the coil.
$(3)$ Length of the coil $(l)$.
$(4)$ Permeability of the core material $(\mu)$.