When two pieces of copper are held together and a current is run through the connection, the theoretical resistance could be considered zero, but in practice, it will be a small, measurable amount due to contact resistance. This contact resistance is influenced by factors such as the flatness, smoothness, cleanliness of the surfaces, and the pressure applied to join them. The discussion highlights that the resistance ultimately reflects that of a single piece of copper when adequately joined. The topic of contact resistance is critical in the study of electrical connectors, focusing on achieving reliable and durable connections. Understanding these factors is essential for optimizing electrical conductivity in practical applications.
