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## Homework Statement

http://imageshack.us/a/img29/9056/homeworkprob10.jpg

Given: Va = 8V. Find Vo in the circuit.

## Homework Equations

V = IR,

KVL, KCL

Voltage division:

(voltage across series resistor) = [ (resistance)/(total series resistance) ](total input V)

Current division (only for two resistors in parallel):

(current through parallel resistor) = [ (OTHER resistance)/(sum of resistors) ](total incoming current)

## The Attempt at a Solution

I think you can redraw it like this:

http://img24.imageshack.us/img24/8245/homeworkprob10redraw.jpg

And since 8V = Va across the 4Ω resistor, V = IR means the current in the whole right node means that I = V/R, and then I = 8V / 4Ω

I = 2A in the right branch right?

Then I = 2A also in the 8Ω resistor in series with it,

so then V = IR for the 8Ω resistor means, V = (2A)(8Ω), V = 16V over the 8Ω resistor

Adding these, V = 24V for the entire right branch.

Left branch resistors is simplified to 4Ω and then you can say V = 24V for it because of being in parallel, right?

Then I = 6A for the left because I = V/R --> 24V/4Ω

then that means 8A is supplied from the middle to both,

but then that means V = (3Ω)(8A) means V = 24V through the middle 3Ω resistor

It can't be more than 24V because it's in parallel right? There was no direction given for Va in the first place and that's confusing. The answer for Vo is given so the only thing that would make sense is if V = -24V for the middle 3Ω resistor and then Vo = 48V (which is also the answer, and just thought of this now).

Is there a better way to tell if either the current or potential in the middle branch is + or - then given only Va first? Again, I just figured it out for the middle branch just now but it's still kind of confusing so, thanks anyway.

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