A model train requires 6 V to operate. If the primary coil of its transformer has 240 windings, how many windings should the secondary have if the primary is connected to a 120-V household circuit? V1/V2 = N1/N2 my teacher went over this with the class, and said that N2= 6V/120V(240), so it equals 12. I don't get how he got that answer. Can someone help me to understand please?