Hands- and Minds-on Electricity and Magnetism

The paper describes several interesting school physics experiments from the area of electricity and magnetism found in foreign journals. These experiments may serve as an inspiration for development of similar school physics experiments or modified versions of experiments and for quantitative measurements on such experiments (which are often used just as qualitative experiments in our school practice). As an example we created a slightly modified version of an experiment Magnetic pendulum and measured its motion in various conditions. This experiment is described in more details in the article. Introduction There are many experiments from the area of electricity and magnetism in student’s books for lower or higher secondary schools. But most of these experiments are only qualitative. For example – there is a collection of nice but only qualitative electrostatic experiments with cans. It might be worthwhile to measure various quantities and parameters of these experiments quantitatively (charge, voltage, etc.). It may be interesting for high secondary school students in special seminars and for university students and it could also help to improve the experiments themselves. One of main goals of my work is therefore to do quantitative measurements concerning some commonly used qualitative experiments. The other goal is to find further experiments, to test them (again including quantitative measurements) and to describe them for physics teachers and students. My work should serve mainly for high’s schools students and their teachers and for students of basic physics courses at universities. Literature search As a starting point I searched for school experiments from the above mentioned area described in foreign and Czech books and journals. Most of interesting experiments and ideas I found appeared in foreign journals, namely American Journal of Physics, Physics Teacher and Physics Education. Figure 1 presents the topic areas and the level of 39 articles containing interesting experiments or ideas about teaching electricity and magnetism. Some of these experiments are known in Czech Republic, but I insert them here because the articles present quantitative measurement or new ideas. To describe all the references presented in Fig. 1 would make this article too long so I would like to comment just a few I found most interesting and inspiring. First article I would like to note is named “ ‘Franklin’s Bells’ and charge transport as an undergraduate lab” [1]. Franklin’s Bells is commonly used electrostatic experiment (but it isn't known under this name in Czech Republic). The “bell” consists of a ball oscillating between two plates of charged capacitor. Authors of the article describe some quantitative models and measurements of this experiment. The article named “Demonstrating diamagnetism” [2] contains interesting idea how to demonstrate diamagnetism in high school. The author uses sensitive electronic balance, neodymium magnet and a bismuth sample. He puts the bismuth sample on the balance and tares it. When he puts the magnet near the sample, the balance will register positive “mass” of a few centigrams – the balance actually measures the diamagnetic force. Article named “A Cheap Simple Ammeter for Batteries-and-Bulbs Activities” [3] contains instructions how to make a simple ammeter (Fig.2). I think that such ammeter can be built by students in higher secondary schools in school labs or as homework. 7 WDS'08 Proceedings of Contributed Papers, Part III, 7–11, 2008. ISBN 978-80-7378-067-8 © MATFYZPRESS