Compared with a copper wire, how much must aluminum wire increase in size to have the same conductivity?

The conductivity of a material is influenced by its intrinsic properties and dimensions. Copper has a higher conductivity compared to aluminum due to its atomic structure and electron mobility. To achieve equivalent conductivity using aluminum, it is necessary to increase the cross-sectional area of the wire compared to that of copper.

Specifically, aluminum is approximately 61% as conductive as copper. Therefore, the cross-sectional area of aluminum must be increased to compensate for this lower conductivity. The increase in size required can be calculated using the ratio of their conductivities. Since the conductivity of aluminum is lower, the area must be larger to achieve the same overall conductivity.

The factor required to compare the required size of aluminum wire to achieve the same conductivity as copper is approximately 1.66 times. This means that the aluminum wire must have a cross-sectional area that is 1.66 times greater than the copper wire to equalize the conductivity between the two materials. This is why the correct answer is 1.66 times.