1. The problem statement, all variables and given/known data Sorry in advance for such a basic question, just starting my first electrical engineering course. The question asks if the interconnection of ideal sources is valid. The next part of the question asks us to verify that the total power developed in the circuit equals the total power absorbed. The diagram given is, from the left going clockwise: a -30V ideal voltage source, +10V ideal voltage source, -8V ideal current source. edit: image added as requested: https://ibb.co/eGkEev 2. Relevant equations p = vi 3. The attempt at a solution I gave the sign of each voltage above in lieu of a diagram (negative sign a voltage rise, positive a voltage drop). The 30V and 8V source are developing power, the 10V consuming it. I am not sure how this is a valid circuit given that we have -38V + 10V -> According to KVL shouldn't that equal zero? However, it confuses me as to how this could be valid. According to the answer to a similar question, a circuit is valid when the voltage sources can carry the Amp of current supplied, and the current source can carry the voltage drop required by the interconnection. I don't understand how to calculate whether this is true of a circuit. In the similar question I referenced, which was valid, you first had one 50V source, then a 10V and 40V source, so I suppose you could equate 50 and 40+10 (there was also a 5A source) (the directions in at question were -50, -10, +40, so I wasn't adding them up, just trying to work out why it was considered valid (and I don't know if that is how you go about it anyway). Regarding power absorbed, we are not given the current, so I am unsure how to proceed there.