Why has copper been widely used as line conductors in the past?

• A. Conducts electric current readily
• B. Is plentiful in nature
• C. Can be easily spliced
• D. All of the above

Answer: (D)

Copper is favored as a line conductor because it brings together several practical advantages: it conducts electricity very well due to its low resistivity, meaning less loss and heat for a given size; it is relatively abundant in nature so it could be mined and processed at a reasonable cost; and it can be easily spliced and joined because of its ductility and compatibility with common joining methods. These combined traits—high conductivity, availability, and ease of joining—made copper the standard for many years, so all of the above factors together explain why it was widely used in the past.