Which current changes direction periodically?

Which current changes direction periodically?

• A. Sporadic current
• B. Alternating current
• C. Direct current
• D. All of the above

Answer: (B)

Changing direction periodically means the electrons switch the direction they move in at regular intervals. This is the defining feature of alternating current, where the source reverses polarity and the current flows back and forth in a repeating cycle (such as 50 or 60 times per second in power systems). Direct current, in contrast, moves in one steady direction. The term sporadic current isn’t a standard description of a waveform, and saying all of the above would be inaccurate because not all options involve periodic reversal. So, the current that changes direction periodically is alternating current.

Changing direction periodically means the electrons switch the direction they move in at regular intervals. This is the defining feature of alternating current, where the source reverses polarity and the current flows back and forth in a repeating cycle (such as 50 or 60 times per second in power systems). Direct current, in contrast, moves in one steady direction. The term sporadic current isn’t a standard description of a waveform, and saying all of the above would be inaccurate because not all options involve periodic reversal. So, the current that changes direction periodically is alternating current.