Washington Esthetician State Board Practice Exam

Alternating current (AC) is characterized by which of the following?

1. Constant flow in one direction

2. Rapid and interrupted flow that changes direction

3. Low voltage transmission

4. Unidirectional high current flow

The correct answer is: Rapid and interrupted flow that changes direction

The characteristic of alternating current (AC) is defined by the rapid and interrupted flow that changes direction. In AC, the electric charge periodically reverses direction, which results in a change in the flow of current. This oscillation occurs in a regular pattern, typically in a sine wave form, leading to the current flowing forward and then backward multiple times per second. The nature of AC makes it suitable for powering homes and industries, as it can be easily transformed to higher or lower voltages using transformers, allowing for efficient long-distance transmission of electricity. This ability to change direction and amplitude is also what differentiates it from direct current (DC), where the flow is consistently in one direction. The other options do not accurately describe AC; the flow is not constant in one direction, nor does it relate specifically to low voltage or unidirectional flows characteristic of DC. Understanding this core principle of AC helps in applying the knowledge towards practical applications in various esthetician equipment that utilize electrical modalities, such as for facials or skin treatments.