1. The problem statement, all variables and given/known data Determine the missing quantity in the circuits in figure below. 2. Relevant equations P = IV = V^2 / R V = IR 3. The attempt at a solution From the diagram, I know the current is flowing opposite to the reference direction (because of the negative current). I used the equation, P = VI. So, -20 W = V (-2 A)... I get V is equal to 10 V. It says something is wrong, what am I doing wrong? I know since the power is negative, and due to Passive Sign Convention, it is supplying power. I'm kind of stuck as to why it doesn't work out the way I did it. Thanks.