Corrente parasitas : uma abordagem para o ensino médio com ênfase na experimentação

Abstract

The present work aimed to elaborate and implement in the classroom a series of experimental practices in order to inserting a eddy currents contents in the high school Physics classes. The project was applied to a third year high school class Cremilda Oliveira Viana State School in Primavera do Leste - MT. Foucault's currents (or eddy currents), are induced in non-magnetic metal by varying a magnetic field. These currents are of great importance in industrial technological applications, either for their desirable effects, such as train braking, or for undesirable effects, such as in transformer cores. Although they are not part of the high school curriculum and are not considered in textbooks, they are extremely rich for the teaching of physics, because, for their understanding, it is necessary to approach and relate various concepts such as magnetic field, magnetic flux, electromagnetic induction and Lenz's law. The educational product entitled Foucault's Currents - Paths for Experimentation, brings instructional material for development and exploration of 05 (five) experiments: three-dimensional perception of magnetic field lines, magnetic train mini prototype, magnetic damping, magnetic ramp and magnetic brake. For each of the experiments, suggestions for exploring related content, discussion proposals, and learning assessment are presented. As a result of our work, we were able to see a conceptual evolution that students were buying about electromagnetic induction, often not achieved in classroom, and how this effect is directly linked to eddy current. Still, the students are motivated, interested, participating and, importantly, show great interest in continuing to have experimental activities.