ARRL Technician Practice Exam

What is the name for a current that flows only in one direction?

1. Alternating current

2. Resistance current

3. Variable current

4. Direct current

The correct answer is: Direct current

Direct current is the term used to describe electric current that flows consistently in one direction. This type of current is commonly produced by batteries and solar cells, and it is used in various applications, including powering electronic devices and circuits. The defining characteristic of direct current is that its electrons move steadily in one direction, creating a constant voltage. This steady flow is crucial for devices that require a specific voltage level to operate effectively. In contrast, alternating current, which flows in alternating directions, is used in household power supplies and industrial applications. Resistance current and variable current are not standard terms in electrical theory, and do not accurately describe a type of electric current. Therefore, the identification of direct current as the flow of current in one direction is the most accurate and relevant definition in the context of electrical engineering.