In a 1993 book review, E. Pearlstein asks, "Why don't textbook authors begin their discussion of magnetism by talking about magnets? That's what students have experience with." A similar question can be asked, "Why don't professors have students measure the force between permanent magnets in introductory physics labs?" The…

This work provides a missing manual needed to understand permanent magnets (also known as "hard" magnets), the only source of "magnetic induction field B" (units of teslas), often called the magnetic field, that students are familiar with when they confront magnetic force acting on moving charges. Students see this magnetic…

Magnets are familiar objects and yet magnetism as a concept remains challenging. A casual search of YouTube for magnets reveals a staggering number of videos, interesting demos involving electric and permanent magnets, and entire channels devoted to various uses for magnets. It is far more difficult to find descriptions that can help students…

The question of how the processes around the Faraday generator with its rotating magnet should be interpreted has been controversial since its discovery by Faraday. Does the magnetic field rotate together with the rotating magnet or does it remain stationary? Furthermore, does one only need Faraday's flux law to interpret inductive processes, or…

A smartphone magnetometer is used to record the magnetic field of a freely falling point dipole magnet. The recorded magnetic field vs. time data are analyzed in accordance with the spatial dependence of the magnetic field to calculate the acceleration due to gravity g. The experiment gives local g to be 9.79 ± 1.9% m/s[superscript 2].

The Curie temperature, also called the Curie point, is the temperature at which magnetic material undergoes a phase transition from ferromagnetic to paramagnetic properties. The characteristics of permanent magnets appear below the Curie temperature--below 400 °C (673 K) for commercial ferromagnetic materials such as ferrite or neodymium. In…

The article presents the results of an experimental study on the motion of a neodymium magnet on an inclined duralumin plate. During experiments, the time of motion was measured, and the steady-state velocity of the magnet motion was determined. To measure the time, a robotic set was used, which made it possible to measure the time of the motion…

In this article, we outline a demonstration that is relatively simple to perform but whose results require a quite subtle interpretation of Faraday's Law. When a very small magnet is dropped through a coil it can tumble as it falls leading to 'spikes' in the measured emf signal. The experiment, and demonstration, can be used in an introductory…

With the wide availability of strong neodymium magnets, the slow and stately fall of a magnet through a conducting pipe has become a favorite classroom demo for teaching electromagnetic induction, Newton's third law, and Lenz's law. Since Lenz's law is conceptually difficult for some students, several authors have used this demo to explore in…

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…

Electric charges and magnetic poles are often confused in the minds of students. It is convenient to remind them that they only interact when they are in relative motion. The force F on a charged particle q moving with velocity V in a magnetic field B is given by F = qVxB. By Newton's Third Law, the force on magnet producing the field B is equal…

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.…

This study demonstrated that the constant average speed of a dynamic car could be measured and calculated using the smartphone magnetometer. The apparatus setup was built using a dynamic car, a linear track up to 1.50 m, a bunch of magnets, and a smartphone magnetometer application. The smartphone magnetometer application, 'Physics Toolbox Suite',…

In this article, we describe how the Gaussian Gun, a simple configuration of magnets and ball bearings, can be leveraged to connect ideas from physics to representations and ideas that are central to chemistry and challenging for students to learn. In particular, we show how the Gaussian Gun, an arrangement of ball bearings and magnets, models…

Many of the old demonstrations in electricity and magnetism can be performed more effectively and with greater visual appeal by using newly available neodymium magnets and color LEDs. For this reason several demonstrations, commonly used for teaching electromagnetic induction and Lenz's law, have received renewed attention in recent years. In…