A case study about the comprehension of electromagnetic induction in Northern Italy

Abstract

We discuss a study about Italian upper secondary school, undergraduate and graduate students’ and teacher’s misunderstanding in dealing with electromagnetic induction. We suspect that most difficulties, that we found substantially common at all levels of education, come from the very poor link, generally presented in teaching, between the Faraday’s law and the Lorentz force. We also suggest that the understanding of inductive phenomena/problems/exercises could benefit from taking into account also the magnetic vector potential “point of view”.

A High School Teaching/Learning Path on Electromagnetic Induction: A Case Study

“…As we have already observed in [1,2], a significant number of students (in this case as many as 56%) think that the presence / absence of an induced current is to be connected with the angle between the direction of the current and the velocity of the coil ("Currentvelocity angle" category). From some students' observations it seems evident that they are not able to correctly visualize the pattern of the field lines surrounding a very long current carrying wire.…”

“…The difficulties faced by students in dealing with and understanding Electro-Magnetic Induction (EMI) are well known and extensively discussed in the literature. Great efforts have been recently carried on (see [1][2][3][4][5][6][7][8][9] and references therein) by a number of physics education research groups about the teaching/learning problems related to EMI. In recent papers [1,2], we presented a somewhat novel study that compares some conceptual difficulties in understanding the various aspects of the electromagnetic induction phenomenon at various educational degrees (high school students, graduate students and physics teachers) and that shows that these difficulties seem to be independent of the level of education.…”

“…Great efforts have been recently carried on (see [1][2][3][4][5][6][7][8][9] and references therein) by a number of physics education research groups about the teaching/learning problems related to EMI. In recent papers [1,2], we presented a somewhat novel study that compares some conceptual difficulties in understanding the various aspects of the electromagnetic induction phenomenon at various educational degrees (high school students, graduate students and physics teachers) and that shows that these difficulties seem to be independent of the level of education. Almost regardless of the results of the educational research, the Italian ministerial indications about the final exam for scientific high school require knowledge/skills/competences [10] to solve complicated exercises and discuss theoretical questions about EMI and, therefore, request for a robust disciplinary scaffolding at school.…”

“…In the developed path, particular attention has been paid to the induced electromotive force (𝑒𝑚𝑓) as composed of two terms: a transformer term and a motional one. In fact, many works [1][2][3]5] suggest the didactic importance of this fact, but, at the best of our knowledge, there are no documented experimentations of a high school path that explicitly takes into consideration these two terms. Taking into account that the level of scientific knowledge of students who have chosen a university course in scientific disciplines other than Physics, Mathematics, Chemistry or Engineering, we believe that the proposed path is also suited form freshmen in not hard scientific disciplines.…”

“…After a negotiation with the class teacher, we decided that the classroom intervention had to last 5 hours (that means 2 weeks), plus 45 minutes for the final test. The final test was a 6-questions multiple choice questionnaire, the same as that discussed in our previous papers [1,2]. Lectures have been held by MG; notes have been taken by MS while all the lessons have been recorded.…”