If there are more turns of wire on the primary windings of a transformer than on the secondary, what type of transformer is it called?

The scenario described, where the primary winding has more turns of wire than the secondary winding, identifies the transformer as a step-down transformer. This type of transformer is designed to reduce the voltage from the primary side to the secondary side.

In a step-down transformer, the ratio of turns between the primary and secondary windings directly affects voltage output. More turns in the primary winding compared to the secondary means that the voltage is higher in the primary. As the electrical energy is transferred through the transformer, the lower number of turns in the secondary winding results in a lower output voltage. This is essential in applications like converting high voltage power from power lines to a lower, usable voltage for homes and businesses.

While step-up transformers and other types like isolating and auto-transformers serve different functions, they do not apply in this case since the presence of fewer turns in the secondary relative to the primary is the defining characteristic of a step-down transformer.