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].

We have developed new rotors that can be classified into three groups by changing the rotors used in simple motors into various types. Group I has a semicircular shape rather than a perfect circle or square shape, group II has a structure consisting of several closed circles on one plane, and group III has a three-dimensional shape. We wanted to…

In this experiment, students explore the synthesis and physical property characterization of the magnetic material strontium hexaferrite (SrFe[subscript 12]O[subscript 19]). SrFe[subscript 12]O[subscript 19] crystallites are prepared by a simple but fascinating sol-gel autocombustion synthesis. The prepared powder is compacted into pellets and…

This study seeks to determine whether giving an explicit incentive to students in an upper-division first-semester electromagnetism course (EM1), in the form of partial credit for reworking unit exam problems, will improve their problem-solving skills as measured by performance on identical problems on the final exam. Three problems--a primarily…

This paper reports on topic-specific pedagogical content knowledge (PCK) enacted by three pre-service science teachers during their final year school-based internship. An interpretive, qualitative case study was conducted to investigate to what extent the pre-service teachers applied the knowledge taught during a preceding physical science method…

In physics lessons at secondary school and experimental physics courses at universities, the magnetic field inside a current-carrying solenoid is considered quantitatively. The corresponding equations and theories are supported by measuring the magnetic flux density inside the solenoid with a Hall probe. It has already been shown that smartphones…

What colors do you use in class when teaching electromagnetism? For many physics educators we simply use what we learned or what is used in the textbook. Browsing through a large collection of introductory physics textbooks reveals that the vast majority use red for the electric field, blue for the magnetic field, and some shade of green for the…

The momentum is often used to analyse the dynamics of the motion of an experimental interaction between objects. Meanwhile, the interaction force tends to be challenging to observe and obtain. In this study, a simple video-assisted experiment was used to observe the interaction forces during the interaction of two magnetic objects. The interaction…

The directional feature of Earth's geomagnetic field has been contributing to the technological development and prosperity of humankind since the invention of the magnetic compass navigation centuries ago. Today, for instance, magnetoresistance sensors are commonly used in nanosatellites and unmanned aerial vehicles for high accuracy geomagnetic…

Classical magnetic resonance is a phenomenon that occurs when the magnetic moment is exposed to combined strong, constant external, and weak alternating magnetic fields. When the frequency of the alternate magnetic field matches the resonant frequency of the oscillator, the amplitude of its oscillation increases drastically. Since the magnetic…

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…