Easy network analysis question about a problem.

[frozenguy]

Homework Statement

Thanks for looking/responding!
Using node voltage analysis in the circuit, find the current i through the voltage source

The Attempt at a Solution

How do I know what direction the all the currents are going before I start analyzing each node?
I know 2A is going counter clockwise along the bottom left corner, and i is to the right on the branch as labeled.

 

[Saladsamurai]

Homework Statement

Thanks for looking/responding!
Using node voltage analysis in the circuit, find the current i through the voltage source

The Attempt at a Solution

How do I know what direction the all the currents are going before I start analyzing each node?
I know 2A is going counter clockwise along the bottom left corner, and i is to the right on the branch as labeled.

Hi there frozenguy I believe it doesn't matter what direction they are going in. Just assume a direction for each current, label your resistor polarities according to your assumptions, and solve. If you get that a particular current comes back as negative, it just means that your assumption was wrong and that the direction os really the opposite.

You dig?

 

[frozenguy]

Hi there frozenguy I believe it doesn't matter what direction they are going in. Just assume a direction for each current, label your resistor polarities according to your assumptions, and solve. If you get that a particular current comes back as negative, it just means that your assumption was wrong and that the direction os really the opposite.

You dig?

Hi Saladsamurai! Yes I totally dig
I was even kind of thinking it may be like that, because I couldn't see how my professor chose them, but I wanted to make sure because my professor doesn't have the best rep around here.
Awesome, thanks Saladsamurai

 

[Saladsamurai]

Hi Saladsamurai! Yes I totally dig
I was even kind of thinking it may be like that, because I couldn't see how my professor chose them, but I wanted to make sure because my professor doesn't have the best rep around here.
Awesome, thanks Saladsamurai

No problem Just remember that by assuming current direction you are implicitly making assumptions about polarity and source/sinkage.

 

[frozenguy]

No problem Just remember that by assuming current direction you are implicitly making assumptions about polarity and source/sinkage.

Roger that..
Meaning that I need to keep track of what I assumed and make sure I correct it after a negative value is calculate?