Which type of copper conductor has the lowest conductivity and highest resistivity?

The correct choice is drawn copper conductors, which indeed exhibit the lowest conductivity and highest resistivity among the options provided. This is primarily due to the manufacturing process involved in drawing the wire. During this process, the copper is pulled through a series of dies to achieve a specific diameter, which can lead to the formation of a finer grain structure in the material. This fine grain structure can disrupt the electron flow, thereby increasing the resistivity of the conductor compared to other types like hard, soft, or stranded copper.

Stranded conductors, for instance, are made up of multiple smaller wires twisted together, which allows for greater flexibility and surface area, contributing to improved conductivity. Soft copper is typically more malleable and can facilitate better conductivity due to its larger grain structure, while hard copper, which has not been worked as extensively, retains a good level of conductivity as well.

Understanding the relationship between the physical structure of the conductor and its electrical properties is key to knowing how different types of copper behave under various conditions. In applications requiring high conductivity, using drawn copper might not be ideal due to its increased resistivity.