Final answer:
Varying DC is generated by using a full-wave rectifier, which consists of a configuration of four diodes that ensure unidirectional current flow. Diodes are electronic components that allow current to flow in only one direction, effectively converting alternating current (AC) into direct current (DC). This is essential for electronics that operate on a steady DC power supply.
Step-by-step explanation:
Varying DC (direct current) can be generated using a system of diodes in a configuration known as a rectifier. A common rectifier configuration that utilizes four diodes is called a full-wave rectifier. The diodes are arranged in such a manner that regardless of the polarity of the input AC (alternating current), the output will always be unidirectional, or DC. This conversion is crucial for devices that require a steady DC power supply, such as computers and cell phones, but the resultant DC may still contain ripples or fluctuations in voltage.
To achieve a smoother DC output, multiple coils and split rings can be used mechanically, or more typically, electronic measures are taken to reduce the ripple and make the DC output more stable and ripple-free. Diodes naturally allow current to flow in one direction, which is fundamental to their use in constructing rectifiers. When the input AC voltage is transformed to a lower voltage using a transformer, the secondary coil's AC needs to be converted to DC, which the rectifier accomplishes through the one-way conductive nature of diodes.