Which of the following materials is typically used to improve tensile strength in conductors?

The correct answer is that steel is typically used to improve tensile strength in conductors. When considering materials that enhance tensile strength, steel's mechanical properties make it an ideal choice for reinforcing conductors. Steel has a high tensile strength, which means it can withstand considerable stress without breaking. This improves the overall structural integrity of the conductor, allowing it to support heavy loads and resist deformation.

While materials like copper and aluminum are excellent for electrical conductivity, they do not possess the same level of tensile strength as steel. Plastics, although useful in insulation and protecting conductors, do not provide significant tensile strength improvements. Thus, steel is commonly integrated into cable designs and conductor systems, especially in high-load applications, to ensure durability and reliability.