In which type of current does the flow change directions rapidly?

The flow of current that changes directions rapidly is characterized as alternating current (AC). In AC, the electric charge reverses direction periodically, which results in the current flowing first in one direction and then in the opposite direction. This oscillation occurs at a certain frequency, typically measured in hertz (Hz), and is the reason AC is commonly used in electrical power systems for homes and industries.

In contrast, direct current (DC) flows in one direction only, providing a steady voltage without changes in polarity. Static current refers to a situation where electric charges remain stationary and do not flow, while transformer current generally refers to the current involved in transformers, which is largely based on alternating current principles, but does not specifically address the nature of current flow direction changes. Thus, the defining feature of AC is the rapid directional change, validating why it is the correct answer.