What primary function do transformers serve in electrical systems?

Transformers are electromagnetic devices designed specifically to transfer electrical energy between two or more circuits through the process of electromagnetic induction. The primary function of transformers is to change the voltage levels in alternating current (AC) electrical systems, which is essential for efficient power transmission and distribution.

When we say transformers can step up or step down AC voltage, we are referring to their ability to either increase (step up) or decrease (step down) the voltage levels between the primary and secondary windings. This capability is crucial in power systems, as it allows for transmitting electricity over long distances at higher voltages (to minimize losses) and then reducing the voltage to safe levels for residential or commercial use.

The ability to handle both stepping up and stepping down makes transformers versatile and integral to power distribution networks. This adaptability is key in various applications, from powering homes to supplying industrial machinery, ensuring that equipment receives the correct voltage needed for optimal performance.

Considering the other options, transformers do not convert direct current (DC) to alternating current (AC) nor do they generate electrical voltage on their own. They also are not limited to only stepping down voltage; they have the ability to either raise or lower voltage levels as needed. Thus, option C accurately captures the fundamental and