What type of current flows in only one direction?

Direct current (DC) is characterized by the flow of electric charge in one consistent direction. This type of current is often used in batteries and electronic devices where a steady voltage is required for the operation of circuits. In a DC circuit, the polarity remains constant; this means the voltage source maintains its positive and negative terminals, allowing the current to flow continuously in a single path.

In contrast, alternating current (AC) reverses direction periodically, which is why it is commonly used for power distribution in homes and industries, allowing for a more efficient transmission over long distances. Eddy currents and induced currents also have distinct behaviors; eddy currents are loops of electric current induced within conductors by a changing magnetic field, while induced currents refer to currents generated in a conductor due to a changing magnetic environment. Neither eddy currents nor induced currents are defined by the simple rule of flowing in one direction.

Thus, in the context of current flow, the defining characteristic of direct current as flowing uniformly in one direction makes it the correct answer.