The weight of an aluminium conductor as compared to a copper conductor of identical cross-section, for the same electrical resistance, is

50%
60%
100%
150%

The correct answer is C. 100 %.

The resistivity of aluminium is 2.65 x 10-8 ohm-metres, while the resistivity of copper is 1.68 x 10-8 ohm-metres. This means that for the same electrical resistance, an aluminium conductor will need to be 1.65 times thicker than a copper conductor. However, aluminium is only about 60% the density of copper, so the aluminium conductor will only weigh about 100% as much as the copper conductor.

Option A is incorrect because the weight of an aluminium conductor is not 50% of the weight of a copper conductor of identical cross-section.

Option B is incorrect because the weight of an aluminium conductor is not 60% of the weight of a copper conductor of identical cross-section.

Option D is incorrect because the weight of an aluminium conductor is not 150% of the weight of a copper conductor of identical cross-section.