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

Explanation

An electric current can be induced in a coil by flux change produced by another coil in its vicinity or flux change produced by the same coil. However, in both the cases, the flux through a coil is proportional to the current. That is, `Phi_B prop I`.
For a closely wound coil of N turns, the same magnetic flux is linked with all the turns. So, total flux linkage is equal to `NPhi_B`, which can be given by `NPhi_B prop I`
The constant of proportionality in this relation is called inductance.
Inductance depends only on the geometry of the coil and intrinsic material properties. (This aspect is similar to capacitance which for a parallel plate capacitor depends on the plate area and plate separation (geometry) and the dielectric constant K of the intervening medium (intrinsic material property).
Inductance is a scalar quantity.
It has the dimensions of `[ML^2 T^(-2)A^(-2)]` . The SI unit of inductance is henry and is denoted by H. It is named in honour of Joseph Henry who discovered electromagnetic induction in USA, independently of Faraday in England.
There are two type of inductance :
(1) Mutual inductance
(2) Self inductance.