We made these simple transformers in class. This was a step-down transformer with more turns on the primary coil than the secondary coil. It makes the secondary voltage smaller than the primary voltage. Many years ago, classes were somewhat underwhelmed by the concept. They thought that electric current flowed from the primary to the secondary through the iron core. Now I emphasise that the wires are insulated so that is not possible. Thus we now get to have a discussion about the flux in the core. As I understand it, Faraday called it flux because he thought it moved like a current. Apparently it doesn't but this fiction is a brilliant predictor of what actually happens.
