Symmetrical Cubic Arrangements of Resistors: An Experimental Approach

• Autores: Leonardo Motta, Antonio Carlos Fontes Santos
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 61, Nº. 6, 2023, págs. 461-466
• Idioma: inglés
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• Resumen

  • In this work, we present a qualitative experimental activity having as the object of study the cubic arrangements of resistors, using low-cost and easily accessible material. In the theoretical analysis of electrical circuits, we use a tool that is not widely used in physics textbooks, called the midpoint theorem (MPT), which states that the potential of points in a symmetry line is the arithmetic average of the electrical potentials of the circuit terminals, so that the set of midpoints is a collection of equipotential points. From an experimental point of view, the use of incandescent lamps as resistors has provided an excellent visual indication of how the electric current is being distributed, by qualitative comparison between the brightness of the lamps. Consequently, there is a direct visualization of the existing symmetry, illustrating and bringing to the concrete, in a very playful way, a subject considered by students to be abstract and mathematized. The measures of potential differences also allowed, in a very explicit way, the identification of homologous points (equipotential), among which we can highlight the midpoints (elements that are part of the MPT itself).