|Compare alternating current DC a continuous electric current that flows in one direction only, without substantial variation in magnitude|
direct current [%PREMIUM_LINK%] (dĭ-rěkt') Pronunciation Key |
An electric current that moves in one direction with constant strength. Batteries are a source of direct current. Direct current is not used for long-distance power transmission because it is difficult to step up the voltage to a level that is efficient for energy transfer and then to step the voltage back down again for safe domestic use. Compare alternating current. See Notes at current, Tesla.