What formula represents the relationship between voltage and the number of turns of windings in a transformer?

The correct formula that represents the relationship between voltage and the number of turns of windings in a transformer is the one where the ratio of the primary voltage to the secondary voltage is equal to the ratio of the number of turns in the primary coil to the number of turns in the secondary coil. This reflects the fundamental principle of transformers, known as the turns ratio, which states that the voltage across the windings is proportional to the number of turns of wire in each winding.

In practical terms, if you increase the number of turns in the primary winding relative to the secondary winding, this will result in a proportional increase in the primary voltage when compared to the secondary voltage. This relationship is crucial for understanding how transformers step up or step down voltage levels in electrical applications.

The other options do not accurately represent this relationship, making the choice that correctly states the proportionality of voltage and turns ratio the most valid and useful for understanding transformer operation.