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…

When deriving the equation describing the transverse motion of a one-dimensional vibrating elastic string, introductory physics textbooks often assume constant tension and/or small amplitude vibrations. However, these simplifying assumptions are not only unnecessary, but they overlook the elastic nature of the tension and yield an inconsistent…

The traditional treatment of the electric circuit in textbooks can be criticized in at least three respects: A) Knowledge of the global aspects of the electric circuit as a system is essential for a deeper understanding. However, this is not sufficiently emphasized. B) The presentation of the term "potential difference" or…

In this article we show that the electrostatic field intensity of a uniformly charged straight line equals that of the corresponding arc of a circle charged with the same linear density. This new method greatly simplifies the calculation of the electrostatic field of a system consisting of uniformly charged straight lines.

The question of whether Faraday's flux law is universal or whether there are exceptions has long been controversial. This discussion seemed to have recently concluded in favor of the generality of Faraday's Flux Law. The present article raises this question again with the aid of some rather simple measurements carried out on a Faraday generator.…

The abstract definition of electric power as "ability of a voltage source to do work" or quantitatively as "energy per unit charge" is preceded by a qualitative description in terms of the existence of surface charges. These surface charges and the associated electric fields can be demonstrated experimentally and allow a causal…

In this paper, we show a laboratory experience describing the possibility to build a sensor using a coil to measure small thicknesses of materials with the possibility of measuring temperature simultaneously, with the same built sensor. Its operation is based on the following facts: An electric current (a.c), flows through a coil and a magnetic…

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…

Eigenstates of a quantum mechanical system reflect one to one correspondence with energy level. However, in some systems more than one or a group of eigenstates correspond to a single eigenvalue. To introduce more than one eigenstate corresponding to single energy eigenvalue in 1D-harmonic oscillator, we introduce a new perturbation term and find…

This paper describes a number of active learning strategies based on implementing the Raspberry Pi as low-cost single-board computing device for carrying out physics laboratory activities. This Microcomputer-Based Laboratory (MBL) Project has been funded by the Baden-Württemberg Foundation and it encompasses the use of high-accuracy yet…

This is a fundamental and pedagogical work in quantum physics/chemistry, where we try to illustrate the Mulliken's question, "What are the electrons really doing in molecules?". And we also briefly review the development of the most popular numerical approaches in computational chemistry. We examine in a novel approach, how we can…

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…

We look at the problem of the minimum speed of projectiles in a constant gravitational field. In the absence of resistance, the problem may be studied in the frame of a high school curriculum. One needs only Newton's laws and a minimum amount of analytic geometry to compute the orbit, which turns out to be parabolic. Furthermore, in case the…

We calculate the frequency of matter-wave of electrons orbiting the hydrogen nucleus at the ground state. It is the same as the value of light frequency corresponding to the ground state from the Rydberg's formula. The result will stimulate students' interest to further understand the mechanisms of quantum theory.

Students' responses to energy & momentum (EM) concepts were investigated. EM concepts are fundamental and crosscutting in physics. A standardized Energy and Momentum Conceptual Survey (EMCS) test were used to collect quantitative data from 108 first year science students enrolled in a university in Ethiopia. Concentration analysis was used to…