How does a transformer function?

A transformer functions primarily by transferring electrical energy between circuits through electromagnetic induction. This process involves two coils of wire—known as the primary and secondary coils—wrapped around a magnetic core. When alternating current flows through the primary coil, it generates a magnetic field that induces a voltage in the secondary coil. The amount of voltage induced can be adjusted based on the ratio of the number of turns in the primary and secondary coils, allowing the transformer to either increase (step-up) or decrease (step-down) the voltage.

This principle makes transformers essential in electrical systems for efficiently transmitting power over long distances and adapting voltage levels for different applications. Other answer choices do not accurately describe the function of a transformer; for instance, converting direct current to alternating current is not a function of a transformer, nor does it generate energy or store it. Instead, it simply ensures that electrical energy is transferred effectively between different parts of an electrical system.