Which device is typically involved in altering the voltage in power systems?

The device typically involved in altering the voltage in power systems is the transformer. A transformer operates based on the principle of electromagnetic induction, where it transfers electrical energy between two or more circuits through inductively coupled conductors—the transformer windings. It can step up (increase) or step down (decrease) voltage levels depending on the ratio of turns in the primary and secondary coils. This capability is essential for efficiently transmitting electricity over long distances, as it allows for higher voltage levels that reduce energy losses during transmission.

In contrast, capacitors and inductors primarily store energy in electric and magnetic fields, respectively, and are more involved in filtering, tuning, and energy storage applications rather than direct voltage alteration in power systems. An amplifier, while it can increase the power of a signal, does not function to change voltage in the way a transformer does in the context of power distribution. Thus, the transformer's role in managing voltage levels is crucial for the effective operation of electrical power systems.