I'm currently struggling to solve this problem (problem below), I need to find U2(t) but I don't know how. I've only solved problems of this kind with closed circuit. Since the secondary loop is open I2 must be 0.
Our teacher labels voltage sources like current sources and my friend forgot to add the V. U1(t) is a voltage source.
While writing this I got a picture from a friend, is his method correct?