Does a step-up transformer have more or fewer windings on the secondary coil compared to the primary coil?

A step-up transformer is designed to increase voltage while decreasing current. It achieves this by having more windings on the secondary coil compared to the primary coil. In a step-up transformer, the secondary coil has additional turns of wire, which allows it to raise the voltage level when the alternating current flows through it.

The ratio of the number of turns in the primary and secondary coils directly correlates with the voltages: if the secondary coil has more turns than the primary, the voltage will increase. Therefore, the correct choice would indicate that the secondary coil has more windings, reflecting the fundamental operation of step-up transformers.

In essence, the concept revolves around the principle of electromagnetic induction, where the transformation of voltage levels is contingent on the respective number of turns in each coil. The other options do not accurately represent the mechanism of a step-up transformer as they suggest situations that do not apply to the basic functioning of such transformers.