Macro‐micro relationships: the missing link between electrostatics and electrodynamics in students’ reasoning

In analysing students' reasoning about simple electric circuits, it is useful to think in terms of three aspects: (a) quantitative relationships, which are defined by algebraic expressions between circuit parameters; (6) functional relationships, which involve qualitative considerations, and lead to a correct description of the interplay between circuit variables; and (c) processes involving macro‐micro relationships, where the macroscopic circuit parameters are tied with microscopic models and rules. We argue that all three aspects are necessary for a proper understanding of the topic. While there is considerable information about the first two aspects with regard to student reasoning, little is known about the third. In this study, we have investigated this aspect with students in an advanced high school course. We find that even in very simple situations, most students do not tie concepts from electrostatics into their description of the phenomena. This leads to severe inconsistencies in student answers to questions about currents, charges and their sources in an electric circuit. Formal definitions (even when quoted correctly) are not utilized operationally. Consequently, a consistent picture of the mechanisms is usually lacking. This may explain why students cannot conceptualize the electric circuit as a system and appreciate the functional relationships between its parts. Additional informationNotes on contributorsUri Ganiel‡‡Corresponding author. ‡Corresponding author.