I did a lab where I measured temperature and resistance of copper and nichrome w

Question

I did a lab where I measured temperature and resistance of copper and nichrome wires. I plot the graph of the equation: y=0.016x+19.096 which represented R=Rn(1+alpha*t). The problem is that when I made y(resistance) = 0, my x (temperature) was -1,1935 Celsius. This number is unrealistic. So what exactly is the problem, is the line equation for my graph wrong, or is there an underlying physics concept here to learn? Keep in mind that R=0 means that the material is a superconductor so what temperature would make a material a super conductor??? something like that.

Explanation / Answer

You have not mentioned the wire for which this graph you are drawing.Because for both copper and nicrome wire you will have the different equation as both will exhibit different resistance and temperature relation.

Now, coming to the point you are getting absurd unrealistic temperature because it is not necessary that all metals will exhibit superconductivity.Researchers have shown that metals that are good conductor at room temperature are not good superconductors.When it comes to predicting the Tc of metals such as copper and gold, one approach in the literature is to alloy the metal with a small amount of another metal until it becomes superconducting and extrapolate alloy % vs Tc down to 0%. One paper that took this approach yielded predictions of superconductivity in Cu, Ag, and Au to be 7×10107×1010 K, 8×10108×1010 K, and 2×1042×104 K.

I hope it solved your query.

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