Students' Difficulties with Equations involving Circuit Elements

TL;DR

This paper investigates common student difficulties in understanding equations involving circuit elements like resistance, capacitance, and inductance in introductory physics, highlighting persistent conceptual confusions.

Contribution

It identifies specific misconceptions students have about circuit equations and analyzes their performance on related questions in different formats.

Findings

Students struggle to understand resistance independence from potential difference.

Confusions also occur with equations for capacitors and inductors.

Performance issues are consistent across question formats.

Abstract

We discuss an investigation exploring students' difficulties with equations involving resistance, capacitance and inductance. We find that introductory physics students have great difficulty understanding, e.g., how the resistance of an ohmic resistor can be written in terms of the potential difference across it and the current through it, but it does not change when the potential difference across the resistor is varied. Similar confusions arose in problems relating to capacitors and inductors. We discuss these difficulties with equations in the context of introductory physics students' performance on questions about circuit elements both in the free-response and multiple-choice formats.