What is the role of a transformer?

The primary role of a transformer is to change the voltage level of alternating current (AC). Transformers operate on the principle of electromagnetic induction, allowing them to increase (step-up) or decrease (step-down) voltage levels while transferring electrical energy between circuits. This ability to alter voltage is crucial for efficient power distribution systems, where electricity must be transmitted over long distances at high voltages to minimize energy loss and then reduced to lower voltages for safe use in homes and industries.

In most electrical systems, AC is preferred because it can be easily transformed to different voltage levels, which is essential in both generating and utilizing electrical power. Hence, the correct choice accurately reflects the fundamental function of a transformer in electrical applications.