What is a defining characteristic of direct current (DC)?

Direct current (DC) is characterized by a constant polarity, meaning that the electrical current flows in a single direction without reversing. This consistency results in a stable voltage level over time, which is crucial for many electronic devices and applications. The uninterrupted flow of electrical charge allows for predictable performance, particularly in circuits that require steady voltage for operation.

In contrast, alternating current (AC) features variable polarity, where the direction of current flow changes periodically, which is not a trait of DC. Moreover, while AC is associated with varying frequencies based on the supply network, DC does not have a frequency, as it maintains a constant flow rather than switching directions. Lastly, intermittent voltage does not apply to DC, since it typically provides a steady voltage without fluctuations. This steady characteristic makes DC ideal for battery-operated devices, electronics, and applications where consistent power is essential.