High School Students Face the Magnetic Vector Potential: some Relapses in their Learning and Tips for Teachers Dealing with Electromagnetism

University of Milan, Italy. Abstract Although the magnetic vector potential is currently treated at university level in electromagnetism and modern physics courses, in secondary school it is never introduced. On the contrary, a quite important place is given to the electric scalar potential, especially in connection with the description of electrical circuits, thus creating a certain asymmetry in the didactical presentation of the electric and magnetic fields. Here we present the results of an experimentation carried out with 25 secondary school students to whom we have introduced the magnetic vector potential using the integral tools of circulation and flux, in close analogy with the usual presentation of the electrostatic scalar potential in secondary school. Since these mathematical tools are the same that students use for writing Maxwell’s equations, our strategy for the introduction of the vector potential is also useful to strengthen and improving students’ learning of more common and basic concepts in electromagnetism. Besides a description of what can be done in classroom work, here we also present some considerations for teachers to further motivate the introduction of vector potential in secondary school. In particular we deal with some opportunities provided by a re-writing of the Maxwell’s equations in terms of potentials. Therefore, we outline connections between electromagnetism and special relativity, so to highlight the importance of vector potential in addition to the traditional scalar potential in a modern presentation of electromagnetism at high school level.