Which device converts alternating current to direct current?

Which device converts alternating current to direct current?

• A. Power Supply
• B. Inverter
• C. Transformer
• D. Oscillator

Answer: (A)

Converting alternating current to direct current requires rectification and smoothing, which is exactly what a power supply does. It takes AC from the wall and uses diodes to convert it into pulsating DC, then filters and regulates it to provide a steady DC output for electronic devices. An inverter, by contrast, does the opposite: it turns DC into AC. A transformer changes the voltage level of AC while still keeping it as AC, so it doesn’t produce DC. An oscillator generates a periodic AC signal, not a DC output. So the power supply best fits the role of converting AC to DC.

Converting alternating current to direct current requires rectification and smoothing, which is exactly what a power supply does. It takes AC from the wall and uses diodes to convert it into pulsating DC, then filters and regulates it to provide a steady DC output for electronic devices.

An inverter, by contrast, does the opposite: it turns DC into AC. A transformer changes the voltage level of AC while still keeping it as AC, so it doesn’t produce DC. An oscillator generates a periodic AC signal, not a DC output. So the power supply best fits the role of converting AC to DC.