How does an electrical transformer function?

An electrical transformer operates by utilizing electromagnetic induction to increase or decrease the voltage levels of alternating current (AC). It consists of two or more coils of wire wound around a magnetic core. When an alternating current flows through the primary coil, it creates a magnetic field that induces a voltage in the secondary coil.

The ratio of the number of turns in the primary coil to the number of turns in the secondary coil determines whether the voltage is stepped up or stepped down. If the secondary coil has more turns than the primary coil, the voltage is increased (stepped up), while if it has fewer turns, the voltage is decreased (stepped down). This ability to manipulate voltage levels is crucial for the transmission and distribution of electrical power over long distances, making transformers a vital component in the electrical grid.

The other choices do not accurately describe how a transformer works. For example, transforming electrical energy to thermal energy pertains more to heaters rather than transformers, storing electrical energy in a magnetic field is a function of inductors or capacitors but not the primary function of a transformer, and limiting current in a circuit relates to devices like resistors or circuit breakers rather than transformers.