University Students Use of Explanatory Models for Explaining Electric Current in Transitory Situations

摘要

There are many studies on students' understanding of DC circuits in the steady state, but few studies have been made about students' ideas on transient states of movement of charges in a conductor. The traditional Electricity curriculum often involves situations of transient motion of charges such as the process of charging a body (conductor or dielectric), closing or opening the switch in a DC circuit or, circuits charging and discharging capacitors. In this research, we present two questions that have been used to investigate the representations of students about the movement of charges of transients in direct current, which focus on the transition between electrostatics and electrodynamics in first year university undergraduate study. The results obtained show that a significant percentage of students cannot correctly interpret simple transitory state current phenomena. Their explanations fall into two general categories. Firstly, one based on potential difference and secondly, one that excludes current flow in processes of transitory state. Some consequences for teaching are discussed.