The unit of self-inductance and inductance is the henry (H), where 1 H = 1 Ω · s Current changes in a device induce an emf in the device itself, called self-inductance, ε = - L d I d t , where L is the self-inductance of the inductor and d I / d t is the rate of change of current through it.

The self-inductance of a solenoid is L = μ 0 N 2 A l , where N is its number of turns in the solenoid, A is its cross-sectional area, l is its length, and μ 0 = 4 π × 10 -7 T · m/A is the permeability of free space Mutual inductance is the effect of two devices inducing emfs in each other

inductance — property of a device that tells how effectively it induces an emf in another device. self-inductance of a solenoid — L = μ 0 N 2 A l , where N is its number of turns in the solenoid, A is its cross-sectional area, l is its length, and μ 0 = 4 π × 10 -7 T · m/A is the permeability of fre. inductor — part of an electrical circuit to provide self-inductance, which is symbolized by a coil of wire. mutual inductance — geometric quantity that expresses how effective two devices are at inducing emfs in one another.