Why is AC preferable for power transmission over long distances?

• A. It is easier to generate
• B. It can be easily transformed to higher voltages
• C. It does not require transformers
• D. It always produces less heat

Answer: (B)

The preference for alternating current (AC) in long-distance power transmission is primarily due to its ability to be easily transformed to higher voltages using transformers. When transmitting electricity over long distances, increasing the voltage reduces the current for a given amount of power. This is critical because higher currents can lead to greater energy loss in the form of heat due to resistance in the conductors, which can significantly diminish the efficiency of power transmission.

By stepping up the voltage before transmission and then stepping it back down to safer, usable levels at the destination, AC systems can effectively minimize energy losses over large distances. This capability to transform voltages is one of the fundamental reasons for the widespread adoption of AC for power distribution networks, enabling efficient delivery of electricity from generation sites to homes and businesses.