Help with finding the power in this circuit

[edgarpokemon]

Homework Statement

http://www.chegg.com/homework-help/questions-and-answers/interconnection-fig-p25-valid-find-total-power-developed-circuit-interconnection-valid-exp-q22345911

It asks if the circuit is valid, which I assume it is.
It asks for the power developed[/B]

Homework Equations

I tried to do KCL in the 4 loops, but i am confused with the middle node. I assume that the 10v will have a current of 1, for the middle node to equal 0. I did a KCL in the upper left loop and got -13 and on the upper right loop I got -17. I am not sure what i am doing wrong to get the power developed. the lower loops confuse me. Help!
3. The Attempt at a Solution [/B]

 

[gneill]

Check KVL around the outside path.

 

[edgarpokemon]

Check KVL around the outside path.

but there is no resistances, and V=iR? The voltage outside the path do not equate to 0, so is the circuit invalid?

 

[gneill]

but there is no resistances, and V=iR? The voltage outside the path do not equate to 0, so is the circuit invalid?

Sum the potential changes around the closed loop and draw your own conclusion

Edit: I should have been more clear. Sum the potential changes around the outer loop.

 

[edgarpokemon]

Sum the potential changes around the closed loop and draw your own conclusion

aaa so starting from the lower right node, it would be 8+6-4-12=-2, so invalid?

 

[gneill]

aaa so starting from the lower right node, it would be 8+6-4-12=-2, so invalid?

Right.