- #1

Nat3

- 69

- 0

## Homework Statement

I'm confused about how to use KCL when doing Nodal Analysis. Please consider the diagram below:

[PLAIN]http://img27.imageshack.us/img27/4900/20091019131641633915550.jpg

## Homework Equations

My first point of confusion is that the diagram shows the current "4Ix" going up, but I thought current always went from higher voltage to lower voltage? (which would be down, in this case).

I also am very confused on how to setup the KCL equation, as you'll see in my attempt below..

## The Attempt at a Solution

To use KCL, we assume that all of the currents are either entering or leaving the node and then add them up, right? Since one of the currents is already shown as entering, would it be logical to write my equation with them all entering? I tried to write the KCL equation like this:

[PLAIN]http://img651.imageshack.us/img651/6033/codecogseqn.gif

The first term is the current entering from the left, the second is term the current going up -- it's negative because it's entering through the negative sign (ohms law) -- and the third term is the current entering on the right, also negative for the same reason as before.

I know this is wrong, but I've spent hours trying to figure this out and am still totally confused. Please help me understand!

Last edited by a moderator: