1. The problem statement, all variables and given/known data Hello everybody, am confronted with this question: A transformer with 5500 turns in its primary is used between a 240V a.c supply and a 120V kettle. Calculate the number of turns in the secondary. 2. Relevant equations The equation Es/Ep = Ns/Np can be applied in solving the problem. Where Es = e.m.f of secondry. Ep = e.m.f of primary, Ns = number of turns in secondary coil, Np number of turns in primary coil 3. The attempt at a solution Using the formular: Es/Ep = Ns/Np Where Np = 5500turns Ns = ? becuase am required to calculate for it. For Es and Ep, I don't know the value to substitute in for Es and Ep respectively. Whether is the 240V or 120V. I don't know between 240V and 120V the one that is Ep or Es respectively. I can't go further with the calculation since am unable to substitute in the values into the equation correctly. Can sombody help me here please?