Does the resistance of a material vary when introduced into water?

[Cloruro de potasio]

Suppose we have a copper wire, of resistance R, and we introduce it in water, when applying now a certain potential difference between the two ends, will the intensity that circulates through the wire be the same, and therefore also the resistance ?, is there going to be a potential drop due to the resistance presented by water, since it is a dielectric material?

Your answers would help me a lot.

Thanks in advance.

 

[phinds]

What research have you done on this so far? What have you found out?

 

[Cloruro de potasio]

I am preparing a small experimental project for the university on the influence of temperature on the resistivity of metals, and I have seen that one of the possible ways of measuring it is by introducing the material into water and increasing the temperature, but I have not just seen very clear if, when introduced into water, the measures will be correct or if the presence of water (as a dielectric material) will have some influence ...

 

[phinds]

You did not answer my question. What research have you done on this so far? What have you found out? By "this" I mean immersion in water's affect on overall resistance.

 

[ZapperZ]

I am preparing a small experimental project for the university on the influence of temperature on the resistivity of metals, and I have seen that one of the possible ways of measuring it is by introducing the material into water and increasing the temperature, but I have not just seen very clear if, when introduced into water, the measures will be correct or if the presence of water (as a dielectric material) will have some influence ...

You know, this is such a SIMPLE thing to test, especially when you are "... preparing a small experimental project...". Why can't you have a coil of copper wire, measure its resistance with a multimeter, and then immerse it in water at room temperature with the ends sticking out (so that you won't mess up the contact point with your multimeter), re-measure the resistance?

This will tell you almost immediately if immersing it in water will affect the resistance, won't it? What prevented you from doing this?

Zz.

 

[sophiecentaur]

if the presence of water (as a dielectric material) will have some influence

Pure water has a very high resistivity (you refer to it as a dielectric material). Wouldn't immersing a wire in water not be much the same as surrounding it in an insulating sleeve (like most of the 'wires' that people use).
Clue: what's the formula for the equivalent R of two Resistances in Parallel?

 

[Dadface]

There are so many variables here but if there is an effect and its very small how will you measure it?

 

[sophiecentaur]

There are so many variables here

But only a very few important ones if you remember the vast difference between the resistivity of the metal and the dielectric and make some justified approximations.

 

[hutchphd]

If this is a DC measurement, the (real part) of the dielectric constant should not matter. For pure water the conductivity will be small but is there any ionic chemistry with the copper over time? The worst case test might be an "almost shorted" solenoidal coil of wire of considerable length with and without water. And maybe measure the conductivity of the "pure" water after removing the coil at the end.

 

[FactChecker]

To keep things simple, assume that nothing is absorbed and that the material and water stay separate. In that case, the water would be a resister in parallel with the material. Consider the two extremes. If the material is an excellent conductor, the current through water can probably be ignored. On the other hand, if the material is an insulator, the current through the material can probably be ignored. In less extreme cases, you can probably use the formula for parallel resisters.

PS. If there is absorption, the situation is more complicated. Damp soil is a better conductor than dry soil. Water in the soil is a better conductor than air.