**ERIC Number:**EJ892046

**Record Type:**Journal

**Publication Date:**2007-Nov

**Pages:**3

**Abstractor:**As Provided

**ISBN:**N/A

**ISSN:**ISSN-0031-921X

Relating the Stored Magnetic Energy of a Parallel-Plate Inductor to the Work of External Forces

Gauthier, N.

Physics Teacher, v45 n8 p498-500 Nov 2007

Idealized models are often used in introductory physics courses. For one, such models involve simple mathematics, which is a definite plus since complex mathematical manipulations quickly become an obstacle rather than a tool for a beginner. Idealized models facilitate a student's understanding and grasp of a given physical phenomenon, yet they convey the essential elements of a sometimes intricate and abstract physical concept. It is thus worthwhile to use available models, or to develop new ones, for use in the introductory classroom. Early discussions of electric energy storage within the framework of the infinite parallel-plate capacitor model are an excellent case in point. In this case one can show, through relatively simple mathematical manipulations, that the work done by an external agent in order to increase the separation between the plates is equal to the corresponding change in the electrical energy of the system. The purpose of this paper is to show that a similar model can also be used to discuss magnetic energy storage based on a calculation of the work done by the external forces that act on the system, a subject that is greatly neglected at the introductory level. We examine this system next.

Descriptors: Physics, Energy, Magnets, Science Instruction, Introductory Courses, Mathematics, Scientific Concepts, Concept Formation, Models, Teaching Methods, Computation

American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail: pubs@aapt.org; Web site: http://scitation.aip.org/tpt

**Publication Type:**Journal Articles; Reports - Descriptive

**Education Level:**N/A

**Audience:**N/A

**Language:**English

**Sponsor:**N/A

**Authoring Institution:**N/A