How does a transformer affect current in relation to voltage?

A transformer operates on the principle of electromagnetic induction and is designed to either step up or step down voltage. When voltage is increased in a transformer (a step-up transformer), the amount of current must decrease to conserve energy, according to the principle of power conservation (Power = Voltage x Current). This means that while the voltage increases, the current decreases proportionally across the primary and secondary coils of the transformer.

Thus, when one side of the transformer has a higher voltage due to more turns of wire, the current will automatically reduce in order to maintain the energy balance. This relationship between voltage and current through a transformer showcases how they are inversely related when viewed from the context of power conservation.

In a step-down transformer, the opposite occurs, where the current increases while voltage decreases. Therefore, the choice highlighting the decrease in current while increasing voltage accurately reflects the fundamental operation of transformers.