Tubo de raios catódicos: uma abordagem experimental para o ensino de eletromagnetismo no ensino médio

Abstract

For decades, cathode ray tubes (CRTs) were present in people’s homes, playing a part in their daily routines. Televisions, as they were called, fascinated people, yet understanding how they work can be more useful than it seems. This work aims to present a suggested teaching sequence for electromagnetism in high school, using CRTs as an experimental tool and a means of connecting the subject to everyday life. The goal is to utilize Ausubel’s meaningful learning theory and Chevallard’s didactic transposition to form the theoretical basis of the proposal. The chosen research methodology was a qualitative approach, as the intention is to work with students in a formative manner. To relate the content of electromagnetism to CRTs, a bibliographic research was conducted on the historical aspects surrounding the subject and the experiment, as well as the functioning of the tubes. Finally, the teaching sequence was applied to a class of 3rd-year high school students in a public school in the state of Paraná, highlighting difficulties and potential improvements in the sequence. Through its application, it was possible to verify the effectiveness of the method used, which indeed showed gains in interest, motivation, and understanding of the subject.