What diameter wire should be used for particular resistance?

[Kastner86]

Homework Statement

If 49 m of nichrome wire is to have a resistance of 16.0 ohms at 20 degrees Celcius, what diameter wire should be used?

Homework Equations

R = $$\rho$$ x L / A

A = $$\Pi$$ d^2 / 4

The Attempt at a Solution

well i know what I'm looking for, that is d (diameter)

and d = $$\sqrt{}$$(4$$\rho$$L/$$\Pi$$R)

I don't know what the value of $$\rho$$ is.

I know it is supposed to be the resistivity of the material, at a certain temperature, but I have no idea how to include it in the equation.

Please Help!

 

[Delphi51]

You can get an estimate of the resistivity at room temperature here:
http://en.wikipedia.org/wiki/Nichrome

 

[tomcue]

As a scientist, it is important to have complete and accurate information in order to provide a response. In this case, the resistivity of the material is a crucial piece of information that is missing from the given problem. Without knowing the specific resistivity of the nichrome wire, it is not possible to accurately determine the diameter that should be used for the desired resistance.

In general, the diameter of a wire can affect its resistance, as a thinner wire will have a higher resistance than a thicker wire of the same material. However, the resistivity of the material also plays a significant role in determining the resistance of a wire. Therefore, it is important to know the specific resistivity of the nichrome wire in order to accurately determine the appropriate diameter for the desired resistance.

Once the resistivity is known, the equations provided in the problem can be used to calculate the appropriate diameter. It is also important to note that the resistivity of a material can change with temperature, so the temperature at which the resistivity is measured should also be specified. Without this information, it is not possible to accurately determine the appropriate diameter for the desired resistance.