Which type of electric current flows in only one direction?

• A. Alternating Current (AC)
• B. Pulsating Current
• C. Inductive Current
• D. Direct Current (DC)

Answer: (D)

Direct current keeps a fixed polarity, with charges moving steadily in one direction from the negative toward the positive terminal. This is the type of current you get from a battery or a DC power supply, where the direction doesn’t reverse. Because the flow doesn’t swing back and forth, the current maintains the same direction over time, even if its magnitude changes.

Alternating current, by contrast, continually reverses direction, so the flow of electrons switches back and forth many times per second. Pulsating current also flows in one direction, but its strength rises and falls in pulses—its direction stays the same, just not its magnitude. Inductive effects describe how current responds to changing voltage in a circuit with inductors and aren’t a separate category of current by direction alone; inductors influence how current and voltage relate, especially in AC, rather than defining a distinct directional type like DC.

So, the current that flows in only one direction is direct current.