Answer: While AC (Alternating Current) is the predominant method for power generation and distribution, DC (Direct Current) is highly efficient for long-distance and specialized applications.

• AC Transmission: AC systems are widely used due to the ease of stepping up or stepping down voltage with transformers, making them cost-effective for short and medium distances. However, they experience losses from reactive power, skin effect, and corona discharge, which become more pronounced over long distances. AC lines typically use three conductors.

• DC Transmission: DC systems are ideal for long-distance power transmission and submarine cables because they have lower power losses. They do not suffer from reactive power or skin effect, which makes them more efficient. While the terminal equipment (converters) is more expensive, the reduced line losses over long distances often make HVDC (High-Voltage Direct Current) more economical. DC lines require fewer conductors, typically one or two.