How does high voltage transmission reduce losses?

• A. High voltage transmission reduces current and losses.
• B. High voltage transmission reduces the supply voltage to homes.
• C. Low voltage transmission reduces thermal losses.
• D. Transmission lines do not influence losses.

Answer: (B)

The main idea is that power losses in transmission lines come mainly from the current flowing through the line. Heat losses in a conductor scale with the square of the current (I^2R). If you need to move the same amount of power but at a higher voltage, you can reduce the current because P = V I. Lower current means much smaller I^2R losses, so the lines waste less energy as heat.

What happens in the system is that the power is sent at high voltage to minimize losses, and then transformers step the voltage down for distribution to homes. So the purpose of high-voltage transmission is not to lower the voltage to households directly; it’s to carry more power with less loss. The statement about reducing the supply voltage to homes is a downstream step, not the mechanism for reducing line losses.