The measurement of the charge-to-mass ratio, e/m, of the electron is a fundamental part of any study of electricity and magnetism. It is possible to use an apparatus designed to measure e/m for other things, including investigations of electron flow through a near vacuum, measuring a work function, and even exploring some quantum mechanics…

Electromagnetism is a complex topic for students at different educational levels. Perhaps one of the reasons for this is that students are unable to visualize the forces, fields, currents, and other electromagnetism key concepts that are related to the topic. Most teachers address this difficulty by including the use of some technological…

The stately fall of magnets through conducting pipes is a favorite classroom and laboratory activity used in teaching electromagnetic induction, Lenz's law, eddy currents, electromagnetic braking, and even Newton's third law. When a neodymium magnet is used, the terminal velocity is reached in just a few milliseconds as the induced eddy currents…

In one of the Faraday's experiments an electric current is induced in a conducting loop when a magnet in front of it moves towards or away from the loop. While the direction of circulation of the electric current in the loop has only two options, it depends on three experimental conditions that generate eight cases. Even though the Faraday law or…

The magnetic field of Earth, B[subscript e], is an intriguing topic in the introductory physics curriculum that engages students' curiosity and inspires numerous speculations about the nature of this phenomenon. There are several methods for measuring Earth's magnetic field. Probably, the most widespread and visual method of measuring the field in…

Proteins are "magical" workers inside our body, as they accomplish most of the cellular functions. Here we report on a novel approach to teach protein folding and unfolding, using magnets and flexible 3D-printed protein structures. To illustrate this physical process, we used colored circular magnets designed for whiteboards, connected…

In a traditional teaching approach, a physics course begins with mechanics, and generally the braking effect due to magnetic interactions is not mentioned among the various types of friction presented (static, sliding, rolling) because students will discover magnetism only in later chapters. In our didactic experience this traditional choice is…

Measuring permeability in a high school physics course has long been a hard task. However, with the advent of using smartphones in the classroom, it is not only possible but even easily done. This paper offers detailed instructions on how to measure permeability using a smartphone's magnetometer, starting with experimentally discovering the…

Science and engineering students in the second semester of a calculus-based physics sequence typically study and measure the on-axis magnetic field for a multiple, circular turn coil. There are four benefits to this approach: 1) an analytical solution is easily obtained, 2) the coil is easily constructed using tightly wound, high-gauge wire where…

Physics II is an undergraduate course on basic electromagnetism that I teach for engineers, and it includes topics from optics as a natural application. Among the many challenges of conducting video lectures during the local restrictions of the SARS-CoV-2 epidemic was finding demonstration material. In this article, I describe how these…

In this article, we propose a simple and accessible model of a magnetic levitator fitted with a Hall sensor. This model also allows to determine the magnitude of the magnetic field within the levitator working volume. Students can also compare the experimental magnetic field values to reference values in magnetism textbooks. This Arduino-based…

A simple experiment is described to verify the current dependence of Ampère's law for a long straight current-carrying conductor. A narrow and long rectangular multi-loop design is used to increase the strength of the magnetic field in between the long sides. As expected, the magnetic field is found to be linearly proportional to the electric…

An alternative way of introducing magnetism at all levels of education is proposed. It is stressed that magnetism can be introduced through the interaction between current-carrying conductors giving the students, at the same time, the possibility to measure the magnetic permeability [mu][subscript o]. Focusing on currents instead of permanent…

In this work, we made a simple electronic tool called a 'magnetic polarity detector' which can determine the magnetic poles of permanent magnets or electromagnets. We used it in some student experiments in the physics laboratory. For example, determining the magnetic poles of permanent magnets and a current-carrying coils or electromagnets.…

Based on a publication of Assis, where the most straightforward and oldest motor is described, first constructed by Ampère, a simple experiment is added to demonstrate once again, why published explanations about its principle of operation and especial the kind how Newton's 3rd principle is used has to be rejected. Ampère's description of his…