Prof. Dr. Thorsten Jungmann (last updated 2025-09-04)
In the 19th century, the American physicist Joseph Henry (1797–1878) intensively investigated the phenomenon of electromagnetic induction and built powerful electromagnets that served as models for industrial applications. He discovered the principle of electromagnetic induction independently of Michael Faraday, and his work contributed significantly to the development of electrical engineering.
The SI unit of inductance, the henry (H), is named in his honour.
Inductance describes the ability of an inductor or a conductor to store a magnetic field and to induce a voltage when the current changes.
The unit appears in a wide variety of applications in electrical engineering – from transformers through filters and induction furnaces to wireless charging systems. Different inductor sizes and materials lead to specific inductance values, which can lie in the microhenry, millihenry or even nanohenry range.
Reference and further reading:
https://en.wikipedia.org/wiki/Joseph_Henry
Image source: Wikipedia