# Node voltage for simple circuit

This is probably a dumb question but I'm not sure what voltage is on this specific node. Also ignore values, they are random.

Is it considered 0V or +V3?

Then would the voltage drop of R1 be V2 or V2 - V3?

Thanks!

EDIT: FULL PROBLEM The op amp used in an inverting amplifier exhibits a finite input impedance Rin. Model the op amp shown in Fig.844 ... other questions.

This is the model given:

This is the model in the answer solutions they used: also Vx = V1 - V2

My problem is understanding how they combined the inverting amplifier config with this model. Can someone step through how they did this?

I assumed that when they combined a noninverting op amp model with the model given, the v- input would be grounded, however I was wrong I guess. Other than that I think I figured it out.

## 1 Answer

Your circuit grounds V3 on both sides meaning that infinite current flows from V3. This makes it impossible to solve. However, If you removed the ground symbol to the right of V3 then your assumptions are correct I.e. the voltage across the resistor is V2 - V3.