Specific resistivity, parallel design, my half baked thought...

[Bio-Hazard]

I was thinking of parallel and series circuits and how they work, but then I began to think more about how I could apply that same knowledge to a wire in terms of resistivity.

 

I was thinking, well if you add another length piece on, that wouldn't increase electron flow.. that would make it somewhat like a series wouldn't it? But what is the physical effect of adding another piece of wire just to make it longer? that doesn't really do much with resistivity, does it?

 

Then I thought, well wouldn't making the wire bigger make it like a parallel circuit? but somewhat exponential? from what i understand the electron flow increases, thus the bigger wire might seem like a parallel since greater current can go through...

[kamil]

But what is the physical effect of adding another piece of wire just to make it longer? that doesn't really do much with resistivity, does it?

 

It does, because the wire is a resistor itself, if you have one lightbulb in a series ciruit, and you add on an exact light bulb to the circuit, the total reistance would double. So if you make the wiring twice as long the total resistance will double.

[Erasmus00]

I was thinking of parallel and series circuits and how they work, but then I began to think more about how I could apply that same knowledge to a wire in terms of resistivity.

 

The resistance of a wire R is defined by resistivity*L/A. Where L is the length of the wire, and A is the cross sectional area. The resistivity is an innate constant of the material, but if we make the wire longer, we see resistance goes up. Similarly, if we increase the cross-sectional area resistance goes down, as expected.

-Will