Which type of current flows in one direction only?

• A. Pulsating Current
• B. Direct Current (DC)
• C. Alternating Current (AC)
• D. Ripple Current

Answer: (B)

Direct Current (DC) is characterized by the flow of electric charge in a single direction. This type of current is produced by sources such as batteries and solar panels, which provide a constant voltage. The unidirectional flow of electrons in DC means that it provides a steady voltage, making it ideal for applications such as powering electronics, where a stable source of energy is necessary.

In contrast, pulsating current involves changes in voltage that can happen in a waveform, but it does not remain steady like DC. Alternating Current (AC) involves the flow of electric charge that reverses direction periodically, which is common in household electricity and larger electrical systems. Ripple current describes a form of AC that can occur in DC power supplies, where there are slight fluctuations or ripples on a DC signal but it still does not flow in one direction only.

Understanding the differences between these types of currents helps in selecting the right power source for specific applications in aviation and other fields concerning machinery and electrical systems.