Question

Why is electric power transmitted over long distances at high voltage?

• A. To minimize power loses due to Joule's heating
• B. To balance power loses due to Joule's heating
• C. To maximize power loses due to Joule's heating
• D. None

Answer 1

Answer: (A)

The correct option is A To minimize power loses due to Joule's heating
For constant electric power, higher the voltage, lower is the current (as $P=IV$) through the wire. As power loss due to Joule's heating is proportional to $I^2$, for a small current, power loss is also small. So, power is transmitted over long distances at high voltage to minimize power loses due to Joule's heating.