A transformer with a turns ratio greater than one is described as which of the following?

A transformer with a turns ratio greater than one is classified as a step-up transformer because it increases the voltage from the primary winding to the secondary winding. In such transformers, the number of turns in the secondary winding is greater than the number of turns in the primary winding, leading to a rise in voltage.

The principle behind a step-up transformer is based on Faraday's law of electromagnetic induction, which states that the voltage induced in a coil is proportional to the number of turns in the coil. Therefore, a higher turns ratio results in a higher output voltage, making it essential for applications requiring increased voltage, such as in power distribution.

In contrast, a step-down transformer decreases the voltage, with fewer turns in the secondary winding compared to the primary winding. An autotransformer has a single winding that acts as both the primary and secondary, providing variable voltage without isolation. A full-wave transformer refers to the type of rectifier circuit used to convert alternating current to direct current, which is not related to the turns ratio classification of transformers. Thus, the designation of step-up transformer accurately reflects the functionality associated with a turns ratio greater than one.