# Electric Potential at Points within a Circuit

Consider the following circuit consisting of 2 batteries and 2 resistors.

How would I find the value of the potential at points $a$ and $b$?

In my initial attempt I assumed that the value of the current was consistent throughout the loop (which is where I think I went wrong) and tried to use Kirchoff's Loop Rule, giving, but seeing as there are no nodes I'm not sure how to go about solving it after.

Additional Info Edit: Using Kirchoff's, I thus far found:

V1 - R1*I - V2 - R2*I = 0

Solving for current:

I = (V1 - V2) / (R1 + R2)

And so the potential difference across is R1 is V = R1*I = R1*(V1 - V2) / (R1 + R2).

So the potential at a would be V1 - R1*(V1 - V2) / (R1 + R2).

• The current is constant through the loop, so that was fine. Why don't you show us your work so far?
– Chris
Oct 20, 2017 at 21:02
• @Chris I added what I did so far (that didn't result in the correct result). Thanks. Oct 20, 2017 at 21:14

Some comments: first off, $I$ is called "current," not "intensity." More importantly, you say the "potential difference across is V," but you don't clarify across what. And you seem to have solved for in the end the potential difference between b and a rather than the potential at a.