Hint:To address this question, look up the concept of diode, which states that a diode is an electronic system in which electric current flows in only one direction and not in any other. And don't be confused by the various types of diodes; there are power diodes, surface mount diodes, and many others.
Complete step-by-step solution: A diode is used as a rectifier to convert ac into dc. A rectifier is an electrical device that converts alternating current (AC) to direct current (DC) using one or more diodes (DC). It is used for rectification, as seen in the step below, which converts AC to DC. A diode is a semiconductor chip that can only transfer current when it is forward biassed. That is why, during negative cycles, if we use one alternating voltage source instead of a battery, the diode will be reverse biassed and will not allow current to flow. As a result, it can act as a rectifier. It is a system that only allows current to travel in one direction. A built-in electric field is used to accomplish this. Modern diodes are semiconductor diodes, unlike the first diodes, which consisted of red-hot wires running through the centre of a metal cylinder inside a glass vacuum tube. These are made of semiconductor materials, as the name implies.
Note:As radio receiver detectors in the early 1900s. Since early point-contact semiconductor diodes were less stable, vacuum diodes were used more commonly in radios until the 1950s. In addition, most receiving sets had vacuum tubes for amplification and could easily include thermionic diodes, and vacuum-tube rectifiers and gas-filled rectifiers could handle some high-voltage/high-current rectification tasks better than semiconductor diodes (such as selenium rectifiers) that were accessible at the time.