The question of the sources of electric and magnetic fields and their causes has been discussed extensively in the literature over the last decades. In this article, we approach this problem from the unified treatment of electromagnetic fields emphasizing the role of their sources in accordance with the cause-effect relationships. First, we…

In this study, we derived several formulas for the currents induced in a circular loop by a magnet connected to a spring-based simple harmonic oscillation system. In addition, we conducted an experiment for measuring the induced currents and compared the results with the theoretical prediction. It was confirmed that the prediction from the derived…

A significant goal when teaching at the secondary education level is to present the generality of the procedures that are being used to describe a wide range of different physical phenomena. However, this approach is abandoned by physics instructors in many cases since the general mathematical background needed to present the above generality is…

A simple model of parallel motion of two point charges and the subsequent analysis of the electromagnetic field transformation invariant quantity are considered. It is shown that ignoring the coupling of electric and magnetic fields, as is done in some introductory physics books, can lead to miscalculations of the force between moving charges.…

It can readily be demonstrated that when a low frequency alternating voltage is applied to an iron-core coil the impedance is much higher than the direct current resistance of the coil. To understand how the high level of impedance arises it is necessary to explain how magnetic and electrical induction give rise to a current in the coil that…

In an effort to examine students' understanding about the structure of boundary conditions in upper-division courses, think-aloud interviews were conducted in the context of both quantum mechanics and electricity and magnetism. In the quantum mechanics task, students were presented with a standard potential step scenario. In the electricity and…

The 1990 film "The Hunt for Red October" (based on Tom Clancy's 1984 debut novel of the same name) featured actors like Sean Connery and Alec Baldwin, but the star of the movie for physicists was a revolutionary new magnetohydrodynamic (MHD) marine propulsion system. The so-called "caterpillar drive" worked with no moving…

We have developed, implemented, and assessed a teaching-learning sequence that aims to enhance students' understanding of the divergence and curl of electromagnetic fields. We designed guided-inquiry worksheets based on student difficulties we identified during semiquantitative and qualitative studies and discussions in the literature. A multiple…

This paper describes the use of an inexpensive smartphone's magnetic sensor to measure magnetic field components (B[subscript x], B[subscript y] and B[subscript z]) induced by current wires in magnetostatic experiments. The variable parameters used to measure the magnetic sensor's capabilities were: the geometrical shapes of the wire, current…

Many students struggle with the use of mathematics in physics courses. Although typically well trained in rote mathematical calculation, they often lack the ability to apply their acquired skills to physical contexts. Such student difficulties are particularly apparent in undergraduate electrodynamics, which relies heavily on the use of vector…

In this note we synthesize and extend expressions for the magnetic field at the center of very short and very long current-carrying coils. Elementary physics textbooks present the following equation for the magnetic field inside a very long current-carrying coil (solenoid): B[subscript sol] = µ[subscript 0] (N/L) I, (1) where I is the current, N…

This paper focuses on the use of software developed by the authors that allows the visualization of the motion of a charged particle under the influence of magnetic and electric fields in 3D, at a level suitable for introductory physics courses. The software offers the possibility of studying a great number of physical situations that can…

If we drop a magnet through a coil, an emf is induced in the coil according to Faraday's law of electromagnetic induction. Here, such an experiment is done using expEYES kit. The plot of emf versus time has a specific shape with two peaks. A theoretical analysis of this graph is discussed here for both short and long cylindrical magnets.…

There is no doubt that integrated concepts inspire students and take learning to a new level. As we fly, we fly through the magnetic field of the Earth. We used the concepts involved in flying to develop an exercise that bonds geology, physics and life sciences.

Maxwell's discovery of the relation between electricity, magnetism, and light was one of the most important ones in physics. With his added displacement current term, Maxwell showed that the equations of electricity and magnetism produced a radiation solution, electromagnetic (EM) radiation, that traveled with a speed of c=1/v(e0µ0). The…