1. The problem statement, all variables and given/known data a) With the switch open, what is the current I1 ? (A positive sign means that current flows in the direction of the arrow.) b) Once the switch is closed in the circuit, what is the power dissipated in the 47 Ω resistor? c) How much current passes through the closed switch? d) With the switch closed, what is the voltage difference, VA-VB ? 2. Relevant equations junction rule: I3 = I2 + I1 Loop rule(s) 3. The attempt at a solution I have attempted all 4 parts, please check my solutions? (parts a to c should be correct, but d not too sure.) For a) Uses the same picture as part b I believe that because there is a open switch, then the whole circuit became a series. 1st step: I got the Req value = 5ohms + 22ohms + 47ohms + 15ohms = 89ohms. 2nd step: I got the Veq value = 10.0V + (-6.0V) = 4.0v 3rd step: I did I = V/R = 4.0V/89ohms = 0.0449 A = I1. For b) I have very badly drawn out all of the current directions(the switch is also closed) the top loop and the bottom loop would be separate with a junction at the middle piece on either end. First, I got that I2 + I1 = I3. Then, I solved for the top loop, starting at the negative terminal side of the battery with 10V moving clockwise. Top loop(clockwise): +10V1 - 15*I1 - 47*I1 + (0V since i'm assuming no Voltage drop across switch) = 0 Bottom loop(counter clockwise): -5*I2 + 6V2 - 22*I2 + 0V = 0 For the top loop: I isolated I1 and got 10/62 = 0.161 = I1 For the bottom loop: I got 6/27 = 0.222A = I2 Power dissipated in 47 ohm resistor I am assuming would be I1^2 * R = (0.161)^2 * 47 = 1.22 Watts? Part c) I'm not totally sure how I do this one, but I think that the current passing through the closed switch is just I3? which is I3 = I1 + I2 = 0.161 + 0.222 = 0.383A. Part d) For this part.. I am not quite sure. I was thinking of like, VA - VB means we have to get from VB to VA in the circuit. So... like VA - VB = +6V2 - 22*I2 + 47*I1? (going counter clockwise up the loop from the 6V battery.) which would give me VA - VB = 6 - 22(0.222)+47(0.161) = 8.68 V.