- #1

- 599

- 6

## Homework Statement

__Given this circuit, find i.__

## Homework Equations

Nodal analysis, Ohm's law other basic EE equations.

## The Attempt at a Solution

The stuff in blue is given in the problem. The red is my attempt at a solution.

So first off a general question that I have is, when I'm doing nodal analysis can I always say that all of the currents are going out of the node and thus treat them as positives? For an example, in this case I'd say that the current from the V1 node going toward V2 is positive when I'm analyzing node one. But when I'm analyzing node 2, can I say that the same current is going toward V1 or do I have to stay consistent and say that the current is going IN to node 2 at that point?

Here's my attempt, node 1:

(60-V1)/2 + (V2-V1)/8 + V1/10 = 0

node 2:

(V1-V2)/8 + (60-V2)/10 + (3/2)(V1-60) = 0

Simplify and solve the system,

I found

V1 = 44.12 V

V2 = -54.71 V (this makes me question my result, is this a reasonable answer?)

I = V/R = 44.12/2 = 7.94 A.

Incorrect answer.