The discussion revolves around using node voltage analysis to determine the current through a voltage source in a circuit. Participants explore the initial assumptions regarding current direction and the implications of those assumptions on the analysis process.
Participants generally agree that the direction of assumed currents can be arbitrary and that negative results indicate a need to revise those assumptions. However, there is no consensus on the best approach to determining initial current directions.
Participants mention the potential influence of their professor's reputation on their understanding of current direction assumptions, indicating a possible limitation in their learning environment.
frozenguy said: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.
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.Saladsamurai said:Hi there frozenguy
You dig?
frozenguy said: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
Just remember that by assuming current direction you are implicitly making assumptions about polarity and source/sinkage.Saladsamurai said:No problem