Which is NOT true of direct current (DC current)?

The statement that "travels in two directions" is not true of direct current (DC current). In fact, one of the defining characteristics of DC current is that it flows continuously in one direction. This unidirectional flow is important in various applications, such as powering batteries, where a consistent voltage and current direction are essential for optimal performance.

Unlike alternating current (AC), where the flow of electricity periodically reverses direction, DC's consistent flow allows for stable voltage levels, making it ideal for devices that require a steady source of power. The other options accurately describe properties of DC current: it has a constant, even flow and is commonly produced by chemical means, such as in batteries and electrochemical cells. This understanding is crucial in the field of esthetics, where devices may rely on either type of current for treatments like microcurrent facials.