1. The problem statement, all variables and given/known data http://img853.imageshack.us/img853/2038/homeworkprob18.jpg [Broken] (everything copied above is as given, except 'I3' was supposed to just be 'I', but more simple for me if 'I3') Use Ohm's law and KVL to find the value of R 2. Relevant equations V= IR KVL, and maybe KCL: KVL = Summation of potential in a loop = 0 3. The attempt at a solution 150V - 50V - (I1)(20Ω) = 0 100V = (I1)(20Ω) I1 = 5A V (on diagram)= (20Ω)(5A) V = 100V and I just go straight to saying V = 100V over the 5Ω resistor because it is in parallel with V on the diagram, right? So, 100V = (5Ω)(I2) I2 = 20A I1 + I2 = I3 I3 = 25A V= I/R ; R = V/I R = 50V / 25A because 50V was the potential drop across R R = 2Ω I didn't see the potential drop across R until I was halfway posting this, but is this correct anyway? It looks weird, and I do not know what the correct answer is.