Aluminium's lower density reduces cable weight for overhead use Steps: - Identify the main requirements for overhead cables: good electrical conductivity and low weight to minimize support structures. - Compare properties of aluminium and copper: both are excellent conductors, but aluminium has a density of 2.7 g/cm³ versus copper's 8.96 g/cm³. - Determine the advantage: lower density means lighter cables for the same conductivity, reducing sagging and installation costs. - Eliminate unrelated factors like reactivity or corrosion, as they don't affect primary selection for weight. Why B is correct: - Density measures mass per unit volume; aluminium's lower density (2.7 g/cm³) allows thinner, lighter cables with equivalent conductivity, easing overhead suspension per engineering standards for power lines. Why the others are wrong: - A: Reactivity series indicates chemical behavior, but both metals conduct electricity similarly and are protected against corrosion in cables. - C: Aluminium forms a protective oxide coating, unlike the claim; this aids durability, not a reason against its use. - D: Copper is stable and does not react significantly with water, making it suitable but heavier than …