Maintenance Technician 2025 Complete Practice Test

Using transformers makes it possible to reduce the wire size of power distribution lines primarily due to the principle of voltage transformation. Transformers operate on the principle of electromagnetic induction to step up or step down voltages in electrical systems. When the voltage is increased (stepped up) on the transmission lines, the current flowing through the wires decreases, according to Ohm's Law (Power = Voltage x Current).

Since power loss due to resistance in wires is proportional to the square of the current (I^2R losses), reducing the current by stepping up the voltage allows for the use of smaller-sized wires without sacrificing efficiency or performance. The ability to transmit power at higher voltages is essential for long-distance power distribution, as it minimizes both energy loss and the need for larger, heavier gauge wires, thereby reducing costs and improving system efficiency.

In contrast, while generators create electricity, they do not directly influence wire sizing in distribution lines. Resistors are components that limit current flow and can produce heat, but they do not alter the voltage or effectively reduce wire size. Solenoids are electromagnetic devices used typically for control purposes and do not facilitate power distribution resizing. Thus, transformers are key in optimizing the power distribution system by enabling reduced wire sizing effectively.