Final answer:
In an auto transformer, the primary and secondary windings are connected both magnetically and electrically. This ensures energy transfer through both inductive coupling and a shared part of the winding. Step-up transformers increase voltage with more turns on the secondary winding.
Step-by-step explanation:
In an auto transformer, the primary and secondary windings are connected both magnetically and electrically. Unlike in a conventional transformer where the primary and secondary coils are electrically isolated and only linked by magnetic flux, an auto transformer has a part of its winding acting as both the primary and secondary winding. This shared part of the winding facilitates an electrical connection between the primary and secondary sides, as well as the usual magnetic coupling found in all transformers.
The essence of a transformer is to transfer electrical energy between two circuits through inductive coupling. Transformers are essential in electrical power distribution, often used as step-up transformers to increase voltage for long-distance transmission or as step-down transformers to reduce voltage for local distribution to homes and businesses.
To distinguish the primary winding from the secondary winding in a step-up transformer, you would look at the number of loops or turns of wire. A step-up transformer would have a higher number of turns on the secondary winding compared to the primary to increase voltage from primary to secondary.