1. The problem statement, all variables and given/known data We have a transformer with the primary coil carries 120 V and the secondary coil having 6 V. If you change the second coil to have 8V, what is the voltage in the primary coil? 2. Relevant equations My textbook does not have any equations that involve just the voltage of transformers. I do have V2=(N2/N1)V1 Or is just a set up of proportions? Like V1/V2=V1/V2 3. The attempt at a solution 120/6=x/8 so x=160?