Electromagnetics Courses Research Articles

A novel teaching platform design with CAI for EM education

AbstractComputers and multimedia technology can greatly facilitate the visualization of abstract concepts and intangible objects such as electromagnetic waves. An educational design platform is proposed to assist undergraduate students in understanding these waves. At present, most electromagnetics courses still use traditional teaching design ideas, from mathematics to reason, and spend much time on formula deduction. Educational design overturns this idea thoroughly to learn with problems and solve experiments related to uncertain concepts; this design will help undergraduate students learn the basic characters of electromagnetic waves intuitively and more easily. Through the experiment‐simulation method, students can experimentally sample data and process data real‐time using simulation software. In this way, students can grasp the physical meaning of abstract concepts more accurately through experiments; furthermore, computer simulations can show the relationships between parameters more intuitively. Thus, the original intention of teaching aided design is exactly reflected: “see knowledge and learn knowledge.”

The Effectiveness of “Pencasts” in Physics Courses

Pencasts are videos of problem solving with narration by the problem solver. Pedagogically, students can create pencasts to illustrate their own problem solving to the instructor or to their peers. Pencasts have implications for teaching at multiple levels from elementary grades through university courses. In this article, we describe the use of pencasts in a university-level upper-division electromagnetic fields course usually taken by junior and senior physics majors. For each homework assignment, students created and submitted pencasts of ordinary problems several days before the problem set was due. We compare students’ performance in the class (grades for pencast submission excluded) with the pencast submission rate. Students who submitted more pencasts tend to do better in the course. We conclude with some practical suggestions for implementing pencasts in other courses.

Orbits of two electrons released from rest in a uniform transverse magnetic field

Two identical charged particles released from rest repel each other radially. A uniform perpendicular magnetic field will then cause their trajectories to curve into a flower petal pattern. The orbit of each particle is approximately circular with a long period for a strong magnetic field, whereas it becomes a figure-eight for a weak magnetic field with each lobe completed in a cyclotron period. For example, such radially bound motions arise for two-dimensional electron gases. The level of treatment is appropriate for an undergraduate calculus-based electromagnetism course.

The implementation of guided discovery learning method to improve student learning outcomes at electromagnetic control system and operation course

This research is triggered by the learning process that is still yet to direct the active role of students learning. Based on the result of observation that the teacher is more dominant in the activity of learning than the students due to the students were lack of understanding towards the subject matter resulted in the lack of activeness of students in the classroom. Based on the background study, it is needed to apply a method of learning that is able to enhance students’ activity and improving the score. One of them by applied the guided discovery learning method. The goal of this research is to know the learning outcomes improvement of the students when using guided discovery learning method on operated Electromagnetic Control System and Operation course in SMK Muhammadiyah Padang. The type of this research is quasi-experimental with one group pre-test post-test design. The population of this research was second year student of group one that registered at 2015/2016 academic year which 26 person of students. The instruments of research was objective tests that has been conducted a test of the validity, reliability, the difficulty level and the different index level. The data were analyzed by using gain score test. Based on the result, the students who achieve value of minimum completeness criteria (MCC) before using the guided discovery learning method was 7,7%. While the students who achieve minimum completeness criteria after using guided discovery learning method was 87,46%. Based on gained score test, the score of the students were increase in Middle Category. So, the implementation of guided discovery learning method can improve student learning outcomes on Electromagnetic Control System and Operation courses.

MATLAB-Based Interactive Tool for Teaching Electromagnetics [Education Corner

Presents information on the MATLAB-Based Interactive tool for teaching electromagnetics. This was created for a second-year university-level electromagnetics course using a MATLAB-based graphical user interface (GUI). It aims to improve learning outcomes, reduce staff workload, and engage online students through blended learning. The tool allows for the random generation of inputs for a large number of problems, provides automatic feedback when the answers are incorrect, and generates a report when the answers are correct. Examples of electrostatics, magnetostatics, dynamic fields, and transmission lines problem sets are presented.

PENERAPAN METODE BLENDED LEARNING BERBASIS TIK UNTUK MENINGKATKAN PEMAHAMAN KONSEP PADA MATAKULIAH LISTRIK MAGNET II

Blended learning is the integration traditional classroom, e-learning, and selflearning methods using ICT based learning. One of them is through Edmodo supported by sufficient internet facilities. The aim of the research was to know the design of learning methods and the utilization of ICT based of blended learning in order to improve the understanding of the concepts in the 2nd Electromagnetic course. The reaserch was a descriptive class action by using qualitative and quantitative approach. All students of Physics Education in FKIP UST who take the 2nd Electromagnetic course were the subject of research. The sample was 28 students as respondents. The sample taking technique in the research used total sampling technique. The results showed that the utilization of Edmodo as the elearning tools in blended learning method was still at a moderate level. It was beacuse for students who took 2nd Electromagnetic course in 2015/2016 academic year were the first experience were not accustomed to active. Furthermore, it was beacuse of the limited internet connection facility. ICT-based of blended learning method as an appropriate educational technology effectively enough to help the learning process so that the lecturers and students could communicate interactively without place restrictions in anytime and anywhere.Keywords : Blended learning, Edmodo

Equilibrium charge distribution on a finite straight one-dimensional wire

The electrostatic properties of uniformly charged regular bodies are prominently discussed on college-level electromagnetism courses. However, one of the most basic problems of electrostatics that deals with how a continuous charge distribution reaches equilibrium is rarely mentioned at this level. In this work we revisit the problem of equilibrium charge distribution on a straight one-dimensional (1D) wire with finite length. The majority of existing treatments in the literature deal with the 1D wire as a limiting case of a higher-dimensional structure that can be treated analytically for a Coulomb interaction potential between point charges. Surprisingly, different models (for instance, an ellipsoid or a cylinder model) may lead to different results, thus there is even some ambiguity on whether the problem is well-posed. In this work we adopt a different approach where we do not start with any higher-dimensional body that reduces to a 1D wire in the appropriate limit. Instead, our starting point is the obvious one, a finite straight 1D wire that contains charge. However, the new tweak in the model is the assumption that point charges interact with each other via a non-Coulomb power-law interaction potential. This potential is well-behaved, allows exact analytical results and approaches the standard Coulomb interaction potential as a limit. The results originating from this approach suggest that the equilibrium charge distribution for a finite straight 1D wire is a uniform charge density when the power-law interaction potential approaches the Coulomb interaction potential as a suitable limit. We contrast such a finding to results obtained using a different regularised logarithmic interaction potential which allows exact treatment in 1D. The present self-contained material may be of interest to instructors teaching electromagnetism as well as students who will discover that simple-looking problems may sometimes pose important scientific challenges.

Forces on a current-carrying wire in a magnetic field: the macro–micro connection

The classic problem of determining the force on a current-carrying wire in a magnetic field is critically analysed. A common explanation found in many introductory textbooks is to represent the force on the wire as the sum of the forces on charge carriers. In this approach neither the nature of the forces involved nor their application points are fully discussed. In this paper we provide an alternative microscopic explanation that is suitable for introductory electromagnetism courses at university level. By considering the wire as a superposition of a positive and a negative cylindrical charge distributions, we show that the electrons are subject to both magnetic and electric forces, whereas the ionic lattice of the metal is dragged by an electric force. Furthermore, an analysis of the orders of magnitude involved in the problem gives counterintuitive results with valuable educational potential. We argue that this approach allows one to discuss different aspects of the physical knowledge, which are relevant in physics education.

Flux Redux: The Spinning Coil Comes Around Again

An essential laboratory exercise for our lower-division electromagnetism course involves the measurement of Earth’s local magnetic field from the emf induced in a rotating coil of wire. Although many methods exist for the measurement of Earth’s field, this one gives our students some practical experience with Faraday’s law. The apparatus we had been using previously for this activity, as has been described in TPT, is a coil driven by an electric motor at constant angular speed with its axis aligned vertically or horizontally. The emf produced was then used to calculate values for the components of the B field. Although this has produced acceptable results, the rotators have proven to be noisy, both electrically and acoustically, as well as somewhat hazardous. Additionally, the effect of stray fields from magnetic materials in the base and housing of the rotator on our measurements has not been quantitatively assessed. Now worn badly by decades of use, these units are prohibitively expensive to replace. In response to this situation, we have designed, built, and tested a quieter, greener, and more compact apparatus that can be produced cost effectively. As part of the experimental design, we have removed the constraint of constant angular rotation rate for the coil; this turns out to provide a much richer data analysis experience for students.

Experimental Solution to the Laplace Equation, a Tutorial Approach

In this paper, experimental solutions of the electromagnetics Laplace equation are presented. First, the papers review the Laplace problem, then solve it using analytical, numerical and experimental methods and compare them together. It also shows that how useful information can be obtained from a raw Laplace equation data. Several tutorial measurements and discussions have been proposed. This paper can be used as a good educational tool in Electromagnetic and physics courses.

Gender gap or program gap? Students’ negotiations of study practice in a course in electromagnetism

A qualitative study of student perceptions of practice in physics identifies differences by physics program rather than by gender.

A rigorous and simpler method of image charges

The method of image charges relies on the proven uniqueness of the solution of the Laplace differential equation for an electrostatic potential which satisfies some specified boundary conditions. Granted by that uniqueness, the method of images is rightly described as nothing but shrewdly guessing which and where image charges are to be placed to solve the given electrostatics problem. Here we present an alternative image charges method that is based not on guessing but on rigorous and simpler theoretical grounds, namely the constant potential inside any conductor and the application of powerful geometric symmetries. The aforementioned required uniqueness and, more importantly, guessing are therefore both altogether dispensed with. Our two new theoretical fundaments also allow the image charges method to be introduced in earlier physics courses for engineering and sciences students, instead of its present and usual introduction in electromagnetic theory courses that demand familiarity with the Laplace differential equation and its boundary conditions.

University Students' Understanding of Divergence in an Upper-level Electromagnetism Course

University Students' Understanding of Divergence in an Upper-level Electromagnetism Course

A comparison between two didactical approaches on shielding problems in an electromagnetic compatibility course – Analytical method versus simulation method

The subject of electromagnetic compatibility is a compulsory one, taught to students from electrical engineering and applied electronics study programmes. We present a comparative study between the current teaching method of shielding calculation and a new simulation-based teaching approach. In the academic year 2013–2014, the effectiveness of the new method was evaluated by analyzing the answers provided by the students to the items in a questionnaire along with their final lab test scores.

What integration cues, and what cues integration in intermediate electromagnetism

We report on semi-quantitative research into students' difficulties with integration in an intermediate-level electromagnetism course with cohorts of about 50 students. We have found that before they enter the course, students view integration primarily as a process of evaluation, even though viewing integration as a summation process would be more fruitful. We confirm and quantify earlier results that recognizing dependency on a variable is a strong cue that prompts students to integrate and that various technical difficulties with integration prevent almost all students from getting a completely correct answer to a typical electromagnetism problem involving integration. We describe a teaching sequence that we have found useful in helping students address the difficulties we identified.

Calculation of self-field coefficients for 2D magnetostatic systems

Physics and engineering students are introduced to the notion of a demagnetizing field in classical electromagnetism courses. This concept involves a formalism based on an integral formulation for calculating the coefficients of the demagnetizing tensor, i.e., a pure geometric quantity. For self-fields, the observation point is located inside the integration region which in turn leads to discontinuous integrands. Therefore, in order to avoid mathematical inconsistencies, special care must be taken when evaluating self-field coefficients, referred to here as self-terms. Given the complexity of this approach, in particular in 3D, it is certainly interesting from a pedagogical stand point to employ 2D systems as a first step for describing these kinds of coefficients. Thus, in this paper, the generalization of self-terms of the demagnetizing tensor is proven for 2D magnetostatic systems. Nonetheless, the structure of this proof pertains to many other situations given the fact that discontinuous integrands commonly arise in physics (e.g. integral solutions of PDEs which use a Green’s function).

Resonance in metallic nanoparticles: a rigorous formulation of the dipolar approximation

In classical electromagnetism, the interaction of light with matter is introduced through the polarizability of a dipole subject to the local field of nearby atoms, leading to the Clausius–Mossotti rule. The dipolar model is also used to introduce plasmonics and fluorescence to undergraduates in electromagnetism courses: the scattering, absorption and extinction of light by spherical particles are examples of analytical solutions in spherical coordinates. The possible resonance of the interaction between light and metallic nanoparticles is commonly described in terms of the infinite limit of the dipole when its relative permittivity tends towards −2. However, this divergence is physically disruptive and therefore a mathematically sustainable approach is required to describe the resonance that occurs in the interaction between light and a metallic spherical particle. The proposed method removes infinity, enabling a rigorous discussion of the resonance.

Characteristics of Pre-service Physics Teachers' Conceptual Understanding of the Gradient in an Upper-level Electromagnetism Course

Characteristics of Pre-service Physics Teachers' Conceptual Understanding of the Gradient in an Upper-level Electromagnetism Course

Teaching Divergence and Curl in an Electromagnetic Field Course

Based on our experiences in teaching an Electromagnetic Field course, we present a research-based teaching method designed for the concepts of divergence and curl, which are important for the course. Comparing the two concepts which have different definitions and expressions, we guide students to ‘seek the difference in the similarity’ so that they can understand the physical meaning more clearly. Furthermore, with the idea of ‘surface-point-volume’ and ‘line-point-surface’ transformation, students can understand the Gauss' law and Stokes formula more easily. It is proved that the method achieved good practical results.

The premetric approach to electromagnetism in the 'waves are not vectors' debate

A plea for the introduction, in advanced electromagnetics courses, of some basic differential geometric notions: covectors, differential forms, Hodge operators. The main advantages of this evolution should be felt in computational electromagnetism. It may also shed some new light on the concept of material isotropy.