Such a transformer is called a step-up transformer. If the secondary coil has fewer turns than the primary, the output voltage will be less than the input voltage. This type of transformer is called a step-down transformer. In power plants, step-up transformers increase the voltage of the alternating current produced by generators. High voltages make it possible to transmit the current over long distances with only a small loss in power.
Some transformers have special uses.
Instrument transformers are used in measuring extremely large alternating voltages and currents. Variable transformers vary the amount of output voltage delivered to a circuit. How to cite this article.