Calculating electric field of continuous objects using the summation method
Journal article
Authors/Editors
Strategic Research Themes
Publication Details
Author list: Kan Sornbundit
Publisher: IOP Publishing
Publication year: 2025
Journal: Physics Education (0031-9120)
Volume number: 60
Issue number: 3
Start page: 035017-1
End page: 035017-10
ISSN: 0031-9120
eISSN: 1361-6552
URL: https://iopscience.iop.org/article/10.1088/1361-6552/adbe1e
Abstract
A core concept of electrostatics at the university level is calculating the electric field of simple geometric objects with uniformly distributed charges. The conventional calculation technique involves dividing the object into many infinitesimal elements. The total electric field at a point is obtained by summing the electric fields generated by each element vectorially. Therefore, students are required to have prior knowledge of calculus, especially integration. However, based on my experience, some students do not understand why integration is necessary for this problem, often due to an insufficient calculus background. This research proposes an alternative teaching method for finding the electric field of simple geometric objects with uniformly distributed charges (such as a charged rod, ring, and disk). This method involves directly summing the electric fields from each element without using integration, encouraging students to understand the problem from a physics point of view. The calculations require a computer program to perform the summation of many elements, allowing teachers to introduce computer programming or available tools to help students with the calculations. Moreover, videos showing the partitioning of charged objects as the number of elements increases are provided. These visualizations help students understand the importance of summation, leading to a deeper understanding of the concept of integration.
Keywords
electric field