Demonstration of magnetic dipole-dipole interaction by using smartphone pressure sensor

TL;DR

This paper demonstrates a practical method using a smartphone pressure sensor to verify the magnetic dipole-dipole interaction law, confirming the inverse fourth power dependence and calculating magnetic dipole moments.

Contribution

It introduces a hands-on experimental approach employing smartphone sensors to validate magnetic force laws and determine magnetic dipole moments.

Findings

Confirmed the inverse fourth power relationship between magnetic force and distance.

Successfully calculated the magnetic dipole moment from experimental data.

Validated theoretical models through linear plotting of force versus inverse distance to the fourth power.

Abstract

In this paper, we present a hands-on activity designed to verify the dependence of the magnetic force between two identical N35 neodymium disc magnets on their separation distance. Utilizing a weight-measuring device incorporating a smartphone pressure sensor placed inside an inflated Ziplock bag, with a glass plate ensuring perfect contact, we measured the magnetic force with high precision. Our results confirm the established inverse fourth power relationship between magnetic force and distance. The linear plot of magnetic force versus the inverse fourth power of distance corroborates the corresponding theoretical model. From the slope of this linear plot, we have calculated the magnetic dipole moment of each magnet, providing a practical validation of theoretical predictions. This methodology also offers an effective approach for educational and experimental verification of magnetic interactions.