Skip to main content Accessibility help
×
Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-19T05:56:30.701Z Has data issue: false hasContentIssue false

9 - Matter and Electromagnetic Fields

from Part III - Continuous Media

Published online by Cambridge University Press:  14 December 2018

Jean-Philippe Ansermet
Affiliation:
École Polytechnique Fédérale de Lausanne
Sylvain D. Brechet
Affiliation:
École Polytechnique Fédérale de Lausanne
Get access

Summary

The internal energy of the electromagnetic field is distinct from that of the matter exposed to the field. The choice of field variable is determined by physical considerations concerning the electric, displacement, magnetic and induction fields. Legendre transform are worked out in order to define electric and magnetic enthalpies and free enthalpies. Spatial derivatives of the enthalpies yield the force densities that dielectrics and magnets experience in inhomogeneous electric and magnetic induction fields. Either internal energy or electric enthalpy must be used to analyse the force on a dielectric inserted in a capacitor, depending on the constraint (constant charge or constant field). Likewise, internal energy or magnetic enthalpy must be considered to analyse the force on a paramagnetic material inserted in a coil or in between the poles of a magnet. A complete analysis of adiabatic demagnetisation offers an example of application of Mayer’s relation to specific heat at constant induction field or constant magnetisation. The effect is predicted for the case of a paramagnetic material with a magnetisation that obeys Curie’s law.

Type
Chapter
Information
Publisher: Cambridge University Press
Print publication year: 2019

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×