Final answer:
Direct current (DC) flows in one direction, while alternating current (AC) periodically reverses direction. AC has advantages over DC for power transmission. Domestic circuits typically use AC.
Step-by-step explanation:
Direct current (DC) is the flow of electric current in only one direction, while alternating current (AC) is the flow of electric charge that periodically reverses direction. AC current is used for power transmission because it has several advantages over DC. One advantage of AC over DC is that AC can be easily transformed to different voltage levels using transformers. Another advantage is that AC can be transmitted over long distances with less power loss compared to DC.
Domestic circuits typically use AC because AC power is what is commonly provided by power companies. AC power has a frequency of 50 or 60 Hz, which is suitable for household appliances and lighting. In contrast, DC power is often used in small electronics, such as batteries.