Comparing students’ understanding of electric and magnetic fields and forces with parallel multiple-choice questions

Understanding the parallelism between electric and magnetic phenomena can be challenging for students in introductory physics courses. This study compares students’ understanding of electric and magnetic fields and forces using parallel multiple-choice questions. Most of the electricity items were drawn from our previously published Test of Understanding of Electric Field, Force, and Flux (TU-E3F), while the magnetism items were newly developed as parallel questions based on the results of our earlier studies. The participants in the present study were 232 engineering students enrolled in a calculus-based electricity and magnetism course at a private university in the northeast of Mexico. We administered a five-item electricity test and a parallel five-item magnetism test to two independent groups of 116 students each and analyzed item difficulty and response patterns using chi-square tests. In this article, we compare students’ performance on parallel items and identify significant differences in the selection of the correct answers and incorrect answers. We also analyze the items by level of difficulty and identify the most frequent incorrect answers. Analysis of incorrect-answer categories highlighted recurrent difficulties with field representations, superposition, and “larger implies larger” reasoning, as well as interference between electric and magnetic ideas. Based on these results, we provide specific recommendations for improving instruction on these concepts. The analyses and recommendations can serve as valuable resources for physics education researchers and instructors teaching these topics. This study offers insights into how context influences students’ conceptual understanding, with implications for enhancing electricity and magnetism education.