The effect of similar surface features on students’ understanding of the interaction of charges with electric and magnetic fields

The literature in student problem-solving abilities in PER has pointed out that novices tend to focus on the surface features of a problem, instead of the underlying principles. In Electricity and Magnetism (E&M) courses, students can confuse the concepts of electric and magnetic fields, which are often represented in problems with similar surface features. It is important to compare the students’ performance on these type of problems to evaluate their understanding of these topics. With this aim, we conducted a study to explore students’ performance in E&M open-ended problems presented with similar surface features. We applied two versions of a questionnaire, one with electricity and one with magnetism problems, to 322 introductory E&M students. In this study, we present some results focusing on a comparison between students’ understanding of electric and magnetic fields in questions regarding electric charges in uniform fields, both at rest and in motion.