What is described by a transformer turns ratio of 1:10?

A transformer with a turns ratio of 1:10 indicates that for every single turn on the primary coil, there are ten turns on the secondary coil. This configuration results in a higher voltage on the secondary side compared to the primary side, which means that the transformer is designed to step up the voltage.

In this context, a step-up transformer is defined specifically by its ability to increase voltage while decreasing current proportionally. The larger number of turns in the secondary coil means it will output a greater voltage, which is a fundamental characteristic of step-up transformers.

While the correct answer reflects this concept, it is crucial to clarify that a step-down transformer would have a turns ratio that is inversely proportional, such as 10:1, where the primary has more turns and outputs a lower voltage on the secondary side. A phase-shifting transformer is used for altering the phase between input and output and does not necessarily relate to voltage step-up or step-down. An isolation transformer primarily serves to separate different parts of a circuit for safety without altering voltage significantly.

Thus, the notion of a transformer turns ratio of 1:10 best fits the description of a step-up transformer, as it clearly indicates an increase in voltage from primary to secondary.