Question

The following table gives the value of electrical resistivity of some materials.

Material	Copper	Silver	Constantan
Electric resistivity (in $\Omega m$)	$1.62 \times {10^{ - 8}}$	$1.6 \times {10^{ - 8}}$	$49 \times {10^{ - 6}}$

Which one of these materials is the best conductor for electricity?

Answer 1

For solving this question, we need to know the relation between the electrical resistivity and conductivity of the material. From this relation, we can determine the conductivity of the material. Therefore, the material which has the highest conductivity among three given materials, will be our answer.

Complete answer:
We know that resistivity or Electrical resistivity of the material is the resistance of the flow of current from one end to the other in a material. Thus, Electrical resistivity is the reciprocal of electrical conductivity which means that it is inversely proportional to the conductivity of the material.

Hence, as the electrical resistivity of the material increases, the conductivity of the material decreases and vice versa.Among the given material, silver has the lowest electrical resistivity which makes it the best conductor for electricity.

Hence, our answer is silver.

Note: There are few points to keep in mind regarding electrical resistivity and conductivity: First is that the metals are good conductors of electricity. Hence, they have low resistivity. Second, the insulators like rubber, glass, graphite, plastics, etc. have very high resistivity when compared to the metallic conductors. Third, in the semiconductor which comes in between the conductors and insulators the electrical resistivity decreases with the increase in temperature and is also affected due to the presence of impurities in them.