Science QUESTION......

The two commonly used materials for electrical wire is copper and aluminum.

For small size electrical wire, copper is used. For large size electrical wire, aluminum is used. It is because aluminum is cheaper and lighter. However, since its conductivity is not as good as copper, for carrying same current, the size of aluminum wire is larger than that of copper.

Copper is the main materials due to its relatively lower cost. When it is compared with silver in terms of cost and conductability, it wins on balance.