Final answer:
Transformers in electrical plants are typically either single-phase or three-phase, and they transform voltages for efficient long-distance transmission and safe local use.
Step-by-step explanation:
Most of the transformers that you'll find in your plant are either single-phase or three-phase. Transformers are critical devices in the electric power industry, used to step-up voltages before transmitting electricity over long distances or to step-down voltages for safe use in homes and businesses. Transformers utilize magnetic induction, where a change in current in the primary coil induces a current in the secondary coil, thanks to a ferromagnetic core that focuses the magnetic field. They are an essential component in reducing energy losses during transmission and ensuring safety when electricity is distributed to end users.