Which type of electrical current flows in one direction only?

• A. Alternating Current
• B. Direct Current
• C. Static Current
• D. Residual Current

Answer: (B)

Direct Current (DC) is defined as an electrical current that flows in one direction only. This type of current is generated by sources such as batteries and solar cells. In DC, the flow of electric charge is consistent, meaning the voltage remains constant over time and does not change direction.

This property makes DC particularly useful for electronic devices, which require a stable and unidirectional flow of current to function properly. For instance, most small electronics, like smartphones and laptops, operate on DC power.

Comparatively, alternating current (AC) fluctuates and changes direction periodically, which is the standard form of electricity supplied to homes and businesses for powering larger appliances. Static current is more of a concept related to stored charge rather than a flow of electrical current. Lastly, residual current typically refers to the path of unintended leakage current that can occur, often triggering safety devices like circuit breakers but does not represent a distinct type of flow like DC does. Thus, the clarity regarding the nature of direct current distinctly establishes it as the correct answer.