Explain why overhead transmission lines uses aluminum conductors
An aluminum conductor has low density, high ductility, good corrosion resistance, and good conductivity, which makes it suitable to use as an electric conductor for the transmission and distribution of electricity. Copper is heavy, costly, and not easily machineable. Aluminum is light in weight, cheap, readily available, easily machineable.
But when it comes to conductivity, copper is best, it has low resistance to the flow of electrons.