The Autotransformer uniquely features a single winding for both primary and secondary functions, represented by a singular numerical value for its primary voltage, distinguishing it from Step-up, Step-down, and Distribution Transformers. Here option A is correct.
The transformer with a primary voltage rating represented by only one numerical value is the Autotransformer. Autotransformers have a single winding that serves both as the primary and secondary winding.
The primary and secondary circuits are electrically connected, and a portion of the winding is shared between them. As a result, the voltage is tapped at different points along the winding to achieve the desired voltage transformation.
In contrast, both Step-up Transformers and Step-down Transformers have separate primary and secondary windings with distinct voltage ratings. The primary voltage of a Step-up Transformer is lower than the secondary voltage, while in a Step-down Transformer, the primary voltage is higher than the secondary voltage.
Distribution Transformers, on the other hand, typically have multiple tapping points for adjusting voltage levels but are not represented by a single numerical value for the primary voltage. Here option A is correct.
Complete question:
Which transformer has a primary voltage rating that is represented by only one numerical value?
A) Autotransformer
B) Step-up Transformer
C) Step-down Transformer
D) Distribution Transformer