Which of the following statements is true about underground transmission cables compared to overhead lines?

• A. They generally require the same level of maintenance as overhead lines.
• B. They generally have more complex construction and different environmental impacts.
• C. They are always cheaper to install.
• D. They have identical environmental impacts to overhead lines.

Answer: (B)

Underground transmission cables involve buried equipment and special design features that aren’t needed with overhead lines. They must be placed in insulated cables inside conduits or ducts, with joints, terminations, and cooling or thermal management systems, plus access points like vaults or pull boxes. That setup makes the installation process much more involved and costly, compared to simply erecting poles and stringing conductors. The environmental impact also differs: burying cables disturbs soil and groundwater, can affect local ecosystems, and requires careful restoration, while repair work is more invasive and time-consuming because access involves digging. So, underground cables generally have more complex construction and different environmental impacts, which is why that statement is the best fit.