To match the conductivity of copper, how much larger must an aluminum wire be?

The correct choice highlights that aluminum must be approximately 1.66 times larger in cross-sectional area than copper to achieve the same conductivity. This is primarily due to the differences in the electrical conductivity of the two materials.

Copper has a higher conductivity than aluminum, meaning that it can carry the same electrical current with a smaller diameter due to its superior performance in terms of conductivity. When switching to aluminum, which has only about 61% of the conductivity of copper, the cross-sectional area must be increased to compensate for this lower inherent conductivity to ensure that both materials can handle the same electrical load without overheating or losing efficiency.

To achieve equal performance in practical applications, the increase in size is calculated based on this ratio of their conductivities. Approximately, for every unit of cross-sectional area for copper, an aluminum wire must have a cross-sectional area that is roughly 1.66 times greater to match the same level of performance in conducting electricity.