Which device provides direct current and typically flows in one direction?

Which device provides direct current and typically flows in one direction?

• A. Battery
• B. AC Power Supply
• C. Ground
• D. Transformer

Answer: (A)

Direct current means the electric charge flows in one steady direction. A battery does exactly this by converting stored chemical energy into electrical energy and pushing current from its positive terminal through the circuit to its negative terminal. The voltage from a battery remains essentially constant in polarity, so the current stays in one direction. In contrast, an AC power supply provides alternating current, which continually reverses direction. Ground is a reference point, not a power source, and a transformer requires alternating current to operate and cannot generate DC on its own (it changes voltage via a changing magnetic field). So the device that supplies steady, one-way current is the battery.

Direct current means the electric charge flows in one steady direction. A battery does exactly this by converting stored chemical energy into electrical energy and pushing current from its positive terminal through the circuit to its negative terminal. The voltage from a battery remains essentially constant in polarity, so the current stays in one direction.

In contrast, an AC power supply provides alternating current, which continually reverses direction. Ground is a reference point, not a power source, and a transformer requires alternating current to operate and cannot generate DC on its own (it changes voltage via a changing magnetic field). So the device that supplies steady, one-way current is the battery.