World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000165018
Reproduction Date:

Title: Ampere-turn  
Author: World Heritage Encyclopedia
Language: English
Subject: Magnetism, Units of measurement, Magnetic dipole, NI, Magnetic reluctance
Publisher: World Heritage Encyclopedia


The ampere-turn (AT) was the MKS (Meters, Kilograms, Seconds) unit of magnetomotive force (MMF), represented by a direct current of one ampere flowing in a single-turn loop in a vacuum.[1] "Turns" refers to the winding number of an electrical conductor comprising an inductor.

For example, a current of 2A flowing through a coil of 10 turns produces an MMF of 20 AT.

By maintaining the same current and increasing the number of loops or turns of the coil, the strength of the magnetic field increases because each loop or turn of the coil sets up its own magnetic field. The magnetic field unites with the fields of the other loops to produce the field around the entire coil making the total magnetic field stronger.

The strength of the magnetic field is not linearly related to the ampere turns when a magnetic material is used as a part of the system. Also, the material within the magnet carrying the magnetic flux "saturates" at some point, when adding more ampere turns has little effect.

The ampere-turn is equal to 4\pi / 10 gilberts, the equivalent CGS unit.

Alternatively, NI has been used in industry, specifically, US based coil making industries.

See also


  1. ^ "ampere–turn". Merriam-Webster. Retrieved 6 November 2012. 

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.