Quadro AC para o ensino de eletromagnetismo: um recurso didático para aulas práticas em turmas com muitos alunos

Abstract

In this dissertation, we present the Quadro AC (AC is the acronym in English for Alternating Current). It is an educational technology which aims to facilitate the teaching of electrical circuits with alternating current. With it, several experiments can be performed such as serial, parallel and mixed connections; to measure the tension and intensity of electric current during the experiments; explore the operation of a photosensor, a potentiometer, transformer and Thomson ring. It is also possible to approach in an investigative manner the Kirchhoff's laws and the law of Faraday's induction. It can be used in high school, technical and higher courses. Its main points are the user safety, easy handling and replication. The Quadro has a manual that details its construction and allows the teacher to build it with a household tooling and the use of low-cost materials. We explain the detailed operation of each part of the product through its manual and we present a method of application in the classroom with an Investigative Teaching Sequence (ITS) for the Quadro AC. The ITS allows the use of the Quadro by a class with many students in such a way that everyone participates throughout its application. The engagement of the class in the construction of experiments was remarkable. The students explored in an investigative way the elements that compose the Quadro and interacted actively discussing the results produced by each group when performing the proposed tasks. The class analysis were made by the teacher using Venn diagrams. This analysis allowed visualizing the interaction between the components of the Quadro and can provide the teacher with subsidies to make decisions regarding the use of experimental activities based on the theoretical contents presented. The analysis may show the need of changes in procedures as the theory was presented in the class.