Approximately how many miles of transmission lines exist?

• A. Over 30,000 miles
• B. 10,000 miles
• C. 50,000 miles
• D. 5,000 miles

Answer: (A)

The question is about the scale of the transmission network. Transmission lines are the long, high‑voltage links that carry bulk power from generators to substations, spanning large distances across the country. When you look at the entire system, the total length falls in the tens of thousands of miles. About thirty thousand miles is a commonly cited rough total, which makes this option the best fit among the choices. It’s larger than 10,000 or 5,000 miles but not as large as 50,000 miles in typical nationwide estimates, and numbers can vary slightly based on what lines are counted and the year. This helps you appreciate how widespread the grid is and why protection and security around these lines are so important.