What type of transformer has a primary side with 100 turns and a secondary side with 10 turns?

A transformer with a primary side that has more turns than the secondary side is classified as a step-down transformer. In this case, the primary has 100 turns while the secondary has only 10 turns, which indicates that the transformer is designed to decrease voltage from the primary to the secondary side. The ratio of turns between the primary and secondary determines how the voltage and current change as they pass through the transformer.

In a step-down transformer, the output voltage on the secondary side is lower than the input voltage on the primary side. This transformation happens due to the inverse relationship between the turns ratio and voltage. Given that the turns ratio is 100:10 (or simplified to 10:1), for every 10 volts on the primary side, there will be only 1 volt on the secondary side. This makes it suitable for applications where lower voltage is required.

This understanding also clarifies why the other options do not fit this scenario: a step-up transformer would have more turns on the secondary than on the primary, while voltage transformers and current transformers refer to specific applications of transformers rather than the basic principle of step-up or step-down functionality.