Compared with copper, aluminium has which characteristic regarding conductivity?

Compared with copper, aluminium has which characteristic regarding conductivity?

• A. Aluminium has higher conductivity than copper.
• B. Aluminium has about 60% of the conductivity of copper.
• C. Aluminium has the same conductivity as copper.
• D. Aluminium conductivity depends on the cross-sectional area.

Answer: (B)

Conductivity is an intrinsic property that compares how easily a material can carry current. Copper is the standard because it has very low resistivity, so it’s the most conductive among common conductors. Aluminum, while lighter and cheaper, has higher resistivity, which means it conducts less current for the same size and conditions. At room temperature, aluminum conducts about 60% as well as copper, reflecting its higher resistivity. Since conductivity is the inverse of resistivity, this roughly 60% figure comes from aluminum’s resistivity being about 1.6 times that of copper. The cross‑sectional area matters for resistance in a circuit (R = rho × L / A), but it does not change the material’s intrinsic conductivity. A larger cross section reduces resistance for a given length, but the fundamental ability of aluminum to conduct compared with copper remains about 60%.

Conductivity is an intrinsic property that compares how easily a material can carry current. Copper is the standard because it has very low resistivity, so it’s the most conductive among common conductors. Aluminum, while lighter and cheaper, has higher resistivity, which means it conducts less current for the same size and conditions. At room temperature, aluminum conducts about 60% as well as copper, reflecting its higher resistivity. Since conductivity is the inverse of resistivity, this roughly 60% figure comes from aluminum’s resistivity being about 1.6 times that of copper.

The cross‑sectional area matters for resistance in a circuit (R = rho × L / A), but it does not change the material’s intrinsic conductivity. A larger cross section reduces resistance for a given length, but the fundamental ability of aluminum to conduct compared with copper remains about 60%.