What does polarity describe in direct current (DC) circuits?

• A. The voltage level.
• B. The direction of DC current flow.
• C. The color coding of wires.
• D. The frequency of the current.

Answer: (B)

Polarity is about which part of a DC circuit is at the higher electrical potential and which is at the lower. In direct current, conventional current is defined to flow from the positive side toward the negative side, so the polarity arrangement directly sets the direction the current will travel. Reversing polarity would flip the current direction and can affect how components operate or even cause damage. The other concepts aren’t describing polarity: the voltage level is about how strong the supply is, color coding is just labeling, and frequency isn’t a factor for DC in the same way it is for AC.