1. The problem statement, all variables and given/known data Determine the rms values of the currents of primary and secondary windings of transformer in the network circuit diagram. Transformer is perfect, with ratio 6: 1,and negligible AC component of magnetizing current, is connected to the sinus supply network U1 = 220 V, f = 50 Hz.Ld = 40 mH, R = 0.5 Ω 2. Relevant equations 3. The attempt at a solution My questions is how did we get square wave forms for the currents i1 and i2 , it really confuses me( I found waveforms in the book) .Shouldn't current i1 be a sine current with 90 angle delay behind voltage source.