What component may increase or decrease voltage in a circuit?

A transformer is a critical component used in electrical circuits to either increase or decrease voltage levels. It operates on the principle of electromagnetic induction and is typically composed of two coils of wire, known as the primary coil and the secondary coil, which are wrapped around a magnetic core. When an alternating current flows through the primary coil, it creates a varying magnetic field that induces a voltage in the secondary coil.

The voltage transformation is based on the turns ratio of the coils; if the secondary coil has more turns than the primary, the transformer will step up the voltage. Conversely, if the primary coil has more turns, the transformer will step down the voltage. This capability to adjust voltage levels is essential in electrical distribution systems, where it is necessary to manage voltage changes for efficient power transmission and usage.

Other components such as inductors, resistors, and capacitors perform different functions in a circuit. Inductors store energy in a magnetic field, resistors limit current flow, and capacitors store energy in an electric field. While these components can influence voltage in various ways, only transformers are specifically designed for the purpose of increasing or decreasing voltage values efficiently in an alternating current circuit.