Validated conceptual multiple-choice surveys administered before and after instruction in relevant concepts can be useful tools to gauge the effectiveness of curricula and pedagogical strategies. Here we discuss the use of four different validated surveys to investigate student understanding: The Energy and Momentum Conceptual Survey (EMCS), the…

In the light of own measurements on a Faraday generator, the well-known theories concerning Unipolar Induction and the Faraday paradox seem to be problematic. On the other hand, all results obtained, and all other processes described as a paradox in connection with the Faraday generator can be explained without contradiction based on the theory of…

A magnetic stirrer is an indispensable instrument in any laboratory setting. Commercially available stirrers are costly and have a defined life-span. The construction of a low-cost magnetic stirrer based on pulse width modulation is described. The design reported uses mainly recycled parts which results in a robust and efficient device at a very…

One may be perplexed about the voltage across an inductor, since sometimes it is -LdI/dt, but more commonly it is LdI/dt. We explain why this is so, and point out that in fact, each of them is fine to be used if under its own sign convention (listed in table 2 in the last section of this paper), and the latter, mostly used in circuit equations, is…

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…

Augmented reality (AR) recently shows great potential to facilitate students' learning, especially their learning performance and motivation. However, few studies considered learners' emotional factors such as learning anxiety, which may influence the learning results. This study aims to explore how different experimental conditions (AR &…

In this work, an easy-to-set-up demonstration about electromagnetic induction is presented, where a simple toy electric motor is transformed into a musical instrument. With this creative way to mix physics and music, it is expected to engage and motivate students to learn about the basic concepts of electromagnetism.

Since its debut in Elihu Thomson's 1886 article "Novel Phenomena of Alternating Currents," the Thomson jumping ring apparatus has been a popular and captivating demonstration of magnetic induction. The components are quite simple. There is a solenoid, an iron core, and a ring. The demonstration usually begins with the professor saying…

The net force and net torque exerted by a uniform magnetic field on a rigid current-carrying loop are discussed in all introductory physics textbooks. A notable omission, however, is the discussion of the equilibrium of a deformable current-carrying loop in a uniform magnetic field. In the article, we present such an analysis for the simplest case…

The calculation of the magnetic field produced by a loop current using the Biot-Savart law is a very typical exercise in introductory university physics. However, the cases studied are limited, in most textbooks, only the circular arrangement is treated. In this article, we calculate the magnetic field of an elliptical loop current along an axis…

Electricity and magnetism are fundamental areas of physics and are integral to science curricula at various educational levels. However, this area has been reported to contain several concepts that students find challenging, leading to perspectives that diverge from scientifically accepted views. This study examines the errors made by physics…

The distant magnetic field of a magnetic dipole is usually derived via the magnetic vector potential and substantial vector calculus. This paper presents an alternate proof that is less mathematically intensive, and that ties together various problem-solving tricks (the principle of virtual work, observation that only instantaneous quantities…

Resonance is an important, and rather dramatic, phenomenon in physics. The mechanical case of a mass-spring oscillator is generally the first example that students encounter in introductory courses. In electromagnetism, the resonance in driven RLC circuits is presented in analogy with mechanics, since the mathematical equations describing them are…

Several properties of Earth's magnetic field (field vectors, time dependence) are measured in various locations using a smartphone/tablet magnetic sensor. To enable a proper use of the magnetic sensor as a classroom tool, the exact location of the sensor in the device and its resolution must be identified in a first step. Then, students may…

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…