What materials are commonly used as conductors in electrical systems?

Copper and aluminum are widely utilized as conductors in electrical systems due to their excellent electrical conductivity and relative availability. Copper is particularly favored for its high conductivity, durability, and resistance to corrosion, making it ideal for various wiring applications. Aluminum, while having slightly lower conductivity than copper, is lighter and more cost-effective, which makes it a popular choice for overhead power lines and other applications where weight is a consideration.

Materials like gold and silver, while excellent conductors, are less practical for widespread use due to their high cost. Steel, although used in certain applications like reinforced cables, does not offer the same level of conductivity as copper or aluminum. Plastic, on the other hand, is an insulator rather than a conductor.

Lead and iron are similarly not used as conductors in conventional electrical systems; lead is more associated with batteries and shielding, and iron has low conductivity making it unsuitable for efficient electrical transmission. Thus, the prevalence of copper and aluminum in electrical systems is due to their balance of conductivity, cost, and practical characteristics.