University students’ understanding of the electromotive force concept in the context of electromagnetic induction

© 2016 IOP Publishing Ltd. In this work, we present research on university students' understanding of the concept of electromotive force (emf). The work presented here is a continuation of previous research by Garzón et al (2014 Am. J. Phys. 82 72-6) in which university students' understanding of emf in the contexts of transient current and direct current circuits was analyzed. In the work we present here the investigation focuses on electromagnetic induction phenomena. Three open-ended questions from a broader questionnaire were analyzed in depth. We used phenomenography to define categories and detect lines of reasoning and difficulties in conceptual understanding. Very few students showed a good understanding of the emf concept in electromagnetic induction circuits or an ability to distinguish it from potential difference. Although the prevalences of the responses in the different categories are different, we find that the difficulties are the same in the three universities. Standard instruction does not allow most students to analyze unfamiliar contexts where the answer requires a systemic explanatory model.