In electrical engineering, what does the term "turn ratio" refer to?

The term "turn ratio" is essential in understanding how transformers work in electrical engineering. It specifically refers to the relationship between the number of turns in the secondary winding of a transformer compared to the number of turns in the primary winding. This ratio determines how the transformer alters voltage levels during operation.

For instance, if the secondary winding has more turns than the primary winding, the transformer will step up the voltage; conversely, if it has fewer turns, it will step down the voltage. This relationship is crucial for calculating voltage, current, and impedance transformations within the circuit, making it a foundational concept in the design and implementation of transformers in various electrical systems.

The other options, while relevant in different contexts, do not pertain to the definition of turn ratio. The length of the wire in the transformer, the current flowing through it, or its temperature rating do not influence the turn ratio, which is fundamentally about winding count.