Which device provides alternating current, changing direction at a specific frequency?

Which device provides alternating current, changing direction at a specific frequency?

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

Answer: (A)

Alternating current is a flow that reverses direction periodically, with a fixed rate called the frequency. An AC power supply is designed to generate that kind of output, producing a voltage and current that sweep back and forth at a specified frequency (for example, 50 or 60 Hz in most mains systems). This is exactly what let you power devices that require an alternating waveform. In contrast, a battery provides direct current, which moves in one direction only; a transformer changes voltage levels but needs an existing AC input and doesn’t by itself create the alternating waveform; a ground is a reference point, not a power source. So the device that directly provides alternating current at a defined frequency is the AC power supply.

Alternating current is a flow that reverses direction periodically, with a fixed rate called the frequency. An AC power supply is designed to generate that kind of output, producing a voltage and current that sweep back and forth at a specified frequency (for example, 50 or 60 Hz in most mains systems). This is exactly what let you power devices that require an alternating waveform. In contrast, a battery provides direct current, which moves in one direction only; a transformer changes voltage levels but needs an existing AC input and doesn’t by itself create the alternating waveform; a ground is a reference point, not a power source. So the device that directly provides alternating current at a defined frequency is the AC power supply.