Utilization of Smartphones in Experiments of Measurement of Electron-Mass Charge Ratio

Abstract

In this work, the strength of the magnetic field produced by a Helmholtz coil was measured using a magnetic sensor on a smartphone and the Kelmscott Gauss meter app. The e/m ratio measurement is a well-known experiment in the physics curriculum. We demonstrate that the strength of the magnetic fields involved may be accurately measured by cell phones. In an electron diffraction experiment, the diameter of a circular ring can theoretically be determined using the same method. Our findings indicate that reliable measurements of the charge-to-mass ratio of electrons can be achieved using cell phone cameras and image processing software. When teaching contemporary physics, smartphones and image analysis software trackers can be extremely helpful resources.