# Nodal and Mesh Analysis vs Simple Ohms law?

1. Jan 23, 2014

### influx

At high school we were taught basic circuit formulas such as V=IR, P=IV etc but now I am studying circuits in Engineering (at university)
we have been introduced to the techniques of nodal and mesh analysis.
My question is, when and why do we use these techniques rather than the aforementioned basic ones?

Also, when using V = IR, you just have positive values for voltage and current but with nodal and mesh analysis you can have negative?

I am a newbie to this so if someone could explain in simple terms how the 2 are related that would be great.

2. Jan 23, 2014

### SteamKing

Staff Emeritus
You can use the basic Ohm's Law formulas to analyze very simple circuits without too much trouble. In slightly more complex networks, if you can figure out the equivalent resistance of several discrete components, you're still good to go. However, if you have a very large or very complex network which has a lot of current loops, mesh analysis is the only tool which can be used to analyze such circuits.

Most of the circuits you encounter in your textbook examples are very simple, having only one or two current loops. For analyzing more complex circuits, having many different current sources and/or current loops, the mesh analysis technique will keep your head from exploding.

3. Jan 28, 2014

### influx

Can you use Mesh analysis for simple circuits? E.g. the ones you would usually use V=IR for..

Thanks

4. Jan 28, 2014

### SteamKing

Staff Emeritus
Sure. Mesh analysis employs the same Ohm's law for simple circuits.