Question about Thévenin, Norton, and KVL Sign Conventions

[NeoEnjoyer]

In a basic electronics exercise, when you are asked to apply Norton's or Thévenin's theorem, are they referring to the same thing, just with a different name?


And another question I had is about this correction: In the application of KVL, why do all the I*R terms end up being negative? For example, in V1, the current passes through the positive terminal, while in V2, it passes through the negative terminal, so in V2, it would make sense for the current to be negative.

 

[BradtheRad]

In order for the arrow 'I' to point the direction it does, and for V1 polarity to be oriented as it is...
Then V2 polarity ought to portray the same. But it doesn't. I think the plus and minus are reversed.

 

[FvM]

Branch current and voltage counting direction are just convention, inversing it won't change calculation result. But it's important to use them consistently.

First comment, V1 and V2 have been apparently added by you, I understand that they are simply representing voltage drop caused by branch current. Unfortunately their polarity is inconsistent, all considerations based on V1/V2 polarity are misleading.

You have chosen voltage direction so that current voltage drop counts negative. This choice defines how Va and Vb polarity has to be counted. Second KVL line and resulting expression for I are correct.