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ERIC Number: EJ1177746
Record Type: Journal
Publication Date: 2018-May
Pages: 3
Abstractor: As Provided
ISSN: ISSN-0031-921X
The Electromotive Force in Different Reference Frames
Adler, Charles L.
Physics Teacher, v56 n5 p307-309 May 2018
The electromotive force (EMF) is the work per unit charge around a wire loop caused by a time-varying magnetic flux threading the loop. It is due to a force moving the charges around the loop. This is true whether the change in flux is due to the wire loop being stationary and the field changing in time, or the loop moving through a spatially varying field. In the first case, we say that the time-varying magnetic field induces an electric field that provides the force; in the second, we say that the force is due to the magnetic field acting on the charges in the moving loop. The theory of relativity states that both viewpoints must be equivalent, but it is sometimes difficult to harmonize them.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A