What does the voltage ratio represent in relation to transformers?

The voltage ratio in a transformer specifically represents the proportion of the primary voltage to the secondary voltage. This ratio is fundamental in understanding how transformers work; they either step up (increase) or step down (decrease) voltage levels while maintaining power balance, aside from losses.

For example, if a transformer has a primary voltage of 100 volts and a secondary voltage of 50 volts, the voltage ratio is 2:1, indicating that the primary voltage is double that of the secondary. This relationship is crucial for the design and application of transformers in power distribution systems, as it helps engineers ensure that the correct voltage levels are achieved for various applications.

In contrast to other choices, such as power ratios, resistance ratios, or comparisons between AC and DC, the voltage ratio specifically highlights the equal functional relationship between the voltages on the primary and secondary sides of the transformer, which directly influences how transformers are used in electrical systems.