Does direct current (DC) change the polarity of the voltage?

In the context of electrical systems, direct current (DC) refers to the unidirectional flow of electric charge. This means that the voltage and current maintain a constant polarity over time, unlike alternating current (AC), where the direction of the current and voltage periodically reverses. Because of this unidirectional nature, DC does not change the polarity of the voltage. Therefore, stating that DC does not change its polarity is accurate.

Understanding this concept is essential, especially when working with various electrical components and systems, as it impacts how devices operate and are connected. AC and DC serve different functions in electrical engineering, and recognizing their distinct characteristics is fundamental to effective electrical design and installation practices as outlined in the BICSI IT Systems Installation Methods Manual.