____ current is alternating current

• A. Single phase
• B. Direct current
• C. 3 phase
• D. Pulsating current

Answer: (C)

Alternating current is current that reverses direction periodically. In a three-phase system, there are three sinusoidal currents in separate conductors, each 120 degrees apart, so the overall power delivered is smooth and nearly constant. This is a hallmark of alternating current, distinguishing it from direct current, which flows in one direction only, and from pulsating current, which varies in magnitude but does not reverse direction. Single-phase current is also alternating, but three-phase is a specific common form of AC used in industry because it provides smoother power delivery and more reliable operation.