1. The problem statement, all variables and given/known data I am trying to work out the size of the field coil in a self-exciting generator as well as the size of the induction coil and the speed it all has to move 2. Relevant equations I think Faraday's law is what I need but I am not sure I am not a physics student so finding the right equations and knowing what the symbols mean on the ones I do find has me hung up at the moment so: number of windings = -1*(-voltage/change in (( tesla * area meters squared)/ seconds)) 3. The attempt at a solution if the generator could make 70 kilowatts that would be great, but in the formula is the area of the coil the area of the field coil or the induction coil, and how much current would come out of this? shouldent it be watts and not volts?