The Electron Runaround: Understanding Electric Circuit Basics Through a Classroom Activity

Several misconceptions abound among college students taking their first general physics course, and to some extent pre‐engineering physics students, regarding the physics and applications of electric circuits. Analogies used in textbooks, such as those that liken an electric circuit to a piped closed loop of water driven by a water pump, do not completely resolve these misconceptions. Mazur¹ and Knight,² in particular, separately note that such misconceptions include the notion that electric current on either side of a light bulb in a circuit can be different. Other difficulties and confusions involve understanding why the current in a parallel circuit exceeds the current in a series circuit with the same components, and include the role of the battery (where students may assume wrongly that a dry cell battery is a fixed‐current rather than a fixed‐voltage device). A simple classroom activity that students can play as a game can resolve these misconceptions, providing an intellectual as well as a hands‐on understanding. This paper describes the “Electron Runaround,” first developed by the author to teach extremely bright 8‐year‐old home‐schooled children the basics of electric circuits and subsequently altered (according to the required level of instruction) and used for various college physics courses.