To carry the same current as copper, aluminium conductor requires what characteristic?

To carry the same current as copper, aluminium conductor requires what characteristic?

• A. Larger cross-sectional area
• B. Higher voltage rating
• C. Lower resistance material
• D. Lower temperature rating

Answer: (B)

The main idea is how ampacity depends on resistance and heating. Aluminum conducts with higher resistivity than copper, so for the same length and the same current, it would heat more unless its cross-sectional area is increased. Increasing the cross-sectional area lowers the resistance per length and reduces I^2R heating, allowing the same current to be carried safely. Since aluminum’s resistivity is about 1.6 times that of copper, you typically need roughly 1.6 times more cross-sectional area to match copper’s current-carrying capability. The voltage rating relates to insulation and maximum operating voltage, not how much current the conductor can carry. A lower temperature rating would actually limit current, not enable it.

The main idea is how ampacity depends on resistance and heating. Aluminum conducts with higher resistivity than copper, so for the same length and the same current, it would heat more unless its cross-sectional area is increased. Increasing the cross-sectional area lowers the resistance per length and reduces I^2R heating, allowing the same current to be carried safely. Since aluminum’s resistivity is about 1.6 times that of copper, you typically need roughly 1.6 times more cross-sectional area to match copper’s current-carrying capability. The voltage rating relates to insulation and maximum operating voltage, not how much current the conductor can carry. A lower temperature rating would actually limit current, not enable it.