What is the main difference between transmission and distribution lines?

The main difference between transmission and distribution lines lies in their voltage levels and function within the electrical grid. Transmission lines are engineered to carry high voltage electricity over substantial distances, facilitating the transfer of electric power from generation sites, such as power plants, to substations. This high voltage allows for efficient long-distance transport, reducing energy losses that would occur with lower voltages.

In contrast, distribution lines are responsible for delivering this electricity from substations to end consumers, such as homes and businesses, often at lower voltage levels that are safe and usable for everyday applications. This differentiation in voltage levels is crucial for the safe operation and effectiveness of the electrical supply system.

The other answer choices do not accurately reflect the characteristics of these two types of lines. For instance, transmission lines do not operate at low voltage, as they utilize high voltage for the reasons mentioned. Distribution lines do not carry high voltage electricity; instead, they handle lower voltage electricity suitable for consumer use. Lastly, while some distribution lines may indeed be located underground, not all of them are, as many exist above ground as well. Thus, the distinction of high voltage transport over long distances accurately describes the role of transmission lines.