1. There is a current of 0.25 A in the circuit of the figure What is the value of the resistance R? Hockay so. I know the change of voltage throughout the loop is 0. therefore 0 = E1 - I(R1+R2) - E2 - 1R(unknown) 0 = 6V - 0.25A*18ohm - 12V - 0.25A*R through algebra i get R=42. And thats wrong. So i dontk now what im doing wrong. And it also asks for the power dissipated by R and i dont know whether to use the energy of both batteries or do a long equation with info from the whole circuit or what. I do know how ever that i should use the PR = IV or I^2R or (V^2/R) thanks a bunch.