Which component is responsible for converting AC to DC?

The component responsible for converting alternating current (AC) to direct current (DC) is the diode. A diode is a semiconductor device that allows current to flow in only one direction. This unidirectional flow is crucial in the conversion process of AC, which periodically reverses direction, into a steady flow of DC.

When an AC voltage is applied to a diode, it only conducts during the positive half-cycles of the AC waveform, effectively blocking the negative half-cycles. As a result, the diode allows only the positive portions of the AC signal to pass through, creating a pulsed DC output. This pulsed output can then be smoothed out with additional components, like capacitors, to form a more steady DC voltage.

Other components mentioned have different primary functions. For instance, a transistor is mainly used for amplification and switching, while the function of a capacitor is to store and release electrical energy, which can support smoothing in a rectifier circuit but does not directly convert AC to DC. A resistor is used to limit the flow of current or divide voltages but does not perform any conversion function.