What is the primary function of a transformer in an electrical system?

A transformer plays a crucial role in electrical systems by changing the voltage level within a circuit, which is essential for effective power distribution. This process allows electrical energy to be transmitted over long distances with minimal loss.

By stepping up (increasing) the voltage for transmission, transformers help ensure that the energy reaches its destination efficiently. Upon reaching the end use point, they can step down (decrease) the voltage to a safer level suitable for general consumption, such as in residential or commercial buildings.

Understanding this function is vital for anyone working in electrical systems, as it directly relates to safe and efficient energy use and distribution across various applications. The other answer choices pertain to different functions and devices that, while important, do not capture the primary purpose of a transformer in the context of electrical systems.