which formulas should I use to calculate the potential in points A in both pictures?


Joined Aug 1, 2013
An introductory book, article, or web page about opamps will have the basic feedback theory and equations.

Is this school work?



Joined Mar 31, 2012
Go back and list the basic assumptions that are made when working with an ideal opamp.

If that doesn't help you figure out the answer, post the assumptions that you find here. We will help you have the correct assumption at hand and then help you use them to get to the answer.


Joined Mar 14, 2008
One important point to remember is that, if the op amp circuit is in its linear region with negative feedback, then due to the very high open-loop op amp gain, the op amp (+) input essentially equals the (-) input voltage.


Joined Jun 17, 2014
As is usual with these kinds of sparse questions i have to ask a question myself first before i can give a truly informed answer.

My question here is:
Are the op amps considered to be ideal, or do you have to assume a finite open loop gain?
The answer will be very different depending on the answer to this question because an infinite open loop gain will show perfect behavior while a finite gain will turn up some interesting artifacts that will be observed in most real life circuits. Both of these scenarios are very informative however so i would suggest you look into both.

I can't quite make out the picture notations very well either so i will assume we are talking about a DC circuit.

Also, if the op amps are not ideal, is there any other effect that has to be considered other than the actual open loop gain?

Oh i just noticed that the thread starter only posted one post so far and has not been back for going on nearly a week already.