Which device is used to increase or decrease voltage in an electrical circuit?

The device used to increase or decrease voltage in an electrical circuit is a transformer. Transformers operate on the principle of electromagnetic induction, allowing them to either step up (increase) or step down (decrease) voltage levels while maintaining the same frequency. This makes them crucial in many applications, particularly in power distribution systems where electrical energy must be transported over long distances at high voltages, and then reduced to safer levels for use in homes and businesses.

Transformers consist of two or more coils of wire wound around a magnetic core. When an alternating current (AC) flows through one of the coils (the primary winding), it creates a magnetic field that induces a voltage in the other coil (the secondary winding). The voltage change is determined by the turns ratio of the coils; a higher number of turns in the secondary coil results in increased voltage, while more turns in the primary yields decreased voltage.

While the other devices listed—full wave rectifiers and diodes—are important in converting AC to direct current (DC) and controlling current flow, respectively, they do not serve the function of altering voltage levels in a manner similar to transformers. Additionally, a dashpot is a damping device typically used in mechanical systems and has no relevance to voltage regulation. Therefore