Which kind of drawn copper conductors have the lowest conductivity?

The nature of drawn copper conductors significantly influences their conductivity. In this context, the likelihood of lower conductivity is associated with hard drawn copper conductors. Hard drawn copper is produced through a process of drawing without subsequent annealing, which aligns the copper's crystalline structure in a way that can increase hardness but decrease overall conductivity.

Conductivity in copper conductors can be affected by the presence of dislocations and impurities in the metal's structure. Hard drawn copper has a higher density of these structural defects compared to softer versions like annealed or flexible copper. As a result, the electrical current encounters more resistance when flowing through hard drawn copper, leading to lower conductivity.

Conversely, soft and annealed conductors have been subjected to processes that relieve internal stresses and refine their crystalline structure, allowing for more efficient electron flow. Flexible conductors are often softer due to their construction and additional treatments, which similarly lead to higher conductivity levels. Hence, among these options, the hard drawn copper conductors exhibit the lowest conductivity due to their greater rigidity and structural imperfections.