Which component converts AC to DC?

• A. Transformer
• B. Diode
• C. Capacitor
• D. Resistor

Answer: (B)

A diode is the component that converts alternating current (AC) to direct current (DC). It achieves this by allowing current to flow in only one direction, effectively blocking the reverse flow of current that is inherent in AC systems. When AC voltage is applied to a diode, it permits the positive half of the waveform to pass through while blocking the negative half. This process is essential in various applications, including power supplies, where DC is needed for electronic devices.

In contrast, a transformer is designed to step up or step down voltage levels in AC systems, but it does not convert AC to DC. A capacitor can temporarily store and release electrical energy and is used in smoothing out the output of a rectifier circuit but is not responsible for converting AC to DC. A resistor is a passive component that limits the flow of current in a circuit, but it also does not play a role in the conversion of AC to DC. Hence, among the choices provided, the diode is the correct answer for converting AC to DC.