MTA Transit Electrical Helper (Exam No. 4612) Practice Exam

Aluminum is often chosen for transmission lines primarily because it is lighter compared to copper. This reduced weight permits easier handling and installation, which is particularly beneficial for long spans between transmission towers. The lighter weight decreases the structural requirements for support towers and other infrastructure, allowing for considerable cost savings in building and maintaining these systems.

While aluminum does have other advantages, such as being more cost-effective than copper, which can influence the overall decision, its weight is a critical factor that significantly affects both construction and operational efficiencies for transmission lines. Although aluminum has lower conductivity than copper, its other properties often make it the preferred material for large-scale power transmission in many scenarios.