What are the differences between a virtual node and a physical one

[Ander99]

Homework Statement

Find the differences between a virtual node and a physical one.

Relevant Equations

none

Hi everyone! Can someone explain which are the differences between a physical node and a virtual one and which one is potentially better . I've been looking for information but I haven't found anything.
Thank you a lot.

 

[berkeman]

Homework Statement:: Find the differences between a virtual node and a physical one.
Relevant Equations:: none

Hi everyone! Can someone explain which are the differences between a physical node and a virtual one and which one is potentially better . I've been looking for information but I haven't found anything.
Thank you a lot.

My Google-foo is not helping me on this. Where did you see the term "virtual node"?

 

[gneill]

My Google-foo is not helping me on this. Where did you see the term "virtual node"?

I, too, am at a bit of a loss here. Perhaps something like a virtual ground at an op-amp input? Two (essentially) separated nodes that are constrained to have the same potential via some mechanism that isn't a simple wire connection?

I do recall when studying computer methods for circuit analysis that one technique for implementing nodal analysis involved creating a virtual ground node just "floating in space" rather than choosing an existing node in the circuit. You end up with one extra node equation to write, but since the computer was doing it and presumably the circuit in question had many, many nodes to begin with anyways, it was not a significant cost in complexity.