Energy and its conservation as a structuring axis for the comprehension of electromagnetic phenomena

Abstract

Energy and its conservation law is an articulating concept in physics, and it is present in the teaching of all of its areas, but while in some of them, such as mechanics or thermodynamics, it is presented in an integrated way, in electromagnetism it is presented in a fragmented and incomplete manner. In this paper we propose a didactic sequence for basic university level, which resurfaces the Poynting theorem as an expression of energy’s conservation law in electromagnetism, to account for the energy processes that involve electric circuits as well as interactions between electric and magnetic fields. This sequence has been implemented for several years in a basic electromagnetism course in engineering and answers many authors’ claims that point out the absence of a discussion about the interactions between electromagnetic fields in electric circuits and the energy transfer processes between source and devices.