A pure inductor, in theoretical terms, is an idealized electrical component that consists only of inductance without any resistance or capacitance. It is characterized by its ability to store energy in a magnetic field when current flows through it and to oppose changes in current due to its inductive reactance.

“Purely inductive” refers to a circuit or component that exhibits behavior dominated by inductance, with minimal influence from resistance or capacitance. In such circuits, the phase angle between current and voltage is close to 90 degrees, indicating a purely reactive response.

The main difference between a pure inductor and a real inductor lies in their practical characteristics. A real inductor, while still primarily exhibiting inductive behavior, also includes resistive and sometimes capacitive elements due to the physical properties of its construction materials. These additional elements can affect its performance, especially at high frequencies.

Pure inductance can be found by measuring the inductive reactance of the component at a given frequency using an appropriate testing method, such as an LCR meter or by calculating it using the formula X_L = 2πfL, where X_L is the inductive reactance, f is the frequency, and L is the inductance.

The unit of pure inductance is the henry (H), named after Joseph Henry, which is defined as the amount of inductance when an electromotive force of one volt is induced by a current changing at a rate of one ampere per second. It represents the fundamental unit of inductance in both theoretical and practical electrical engineering applications.