Which term describes the type of current that is produced by multiple phases?

• A. Three-phase
• B. Direct current
• C. Alternating current
• D. Single-phase

Answer: (A)

Multiple-phase power means several AC waveforms are produced and offset in time. The term that describes current produced by multiple phases is three-phase, which uses three sinusoidal voltages 120 degrees apart. This remains alternating current, but specifies a polyphase arrangement. Direct current flows in one direction and does not have phases; single-phase uses only one waveform, not multiple phases; alternating current is the general category for current that reverses direction, while three-phase is a specific type of AC with three phases. In industry, three-phase power provides smoother torque and more efficient operation for motors and large loads.