Hello, I have some doubts in the following problem of a transformer, specially on parts 2 and 4. I would be very grateful if someone could please give me any ideas specially about those parts... 1. The problem statement, all variables and given/known data 3. The attempt at a solution 1) Applying KVL in each mesh: Mesh 1: V1 = jwL1I1 - jwMI2 Mesh 2: V2 = jwMI1 - jwL2I2 2) power for RL? First, apply KVL in each mesh: Mesh 1 : V1 = jwL1I1 - jwMI2 Mesh 2 : 0 = jwMI1 - (jwL2 + RL) I2 get I2, and substitute it in the power function below: P = V I2 = RL I2^2 Regarding M, I only know the formula of M = k sqrt(L1 L2). I wonder if there is another way to get M....Any ideas ? 3) Z1? V1 = Z1 I1 Z1 = V1 / I1 First, apply KVL in each mesh: Mesh 1 : V1 = jwL1I1 - jwMI2 Mesh 2 : 0 = jwMI1 - (jwL2 + jwL) I2 get I2 from equation of Mesh 2, and substitute it in Mesh 1 equation. After that, substitute V1 from Mesh 1 equation into the equation below: Z1 = V1 / I2 = So the result is: Z1 = jwL1 + (w^2 M^2)/(jwL2 + jwL) 4) w? I have absolutely no idea on how to do this part. V and I in phase means : V = Vm cos(wt + 0), I = Im cos(wt + 0) and an ideal trasnformer means that k =1 from the equation for M... Any ideas for this part? Thanks in advance!