Question

Specific resistance of copper, silver and constantan are $1.8\times {10}^{-6}ohmcm$ , $1.6\times {10}^{-6}ohmcm$ and $45\times {10}^{-6}ohmcm$.Which is the best electrical conductor and why?

Answer 1

Hint: In physics, specific resistance or Resistivity of a material is a measure of the resistance, which the material offers for the flow of current through it. It’s an intrinsic property of a material which mainly depends upon composition of the material.

Complete step by step answer:
Since, Resistivity of a material is the measure of its resistance which it offers when current flows in it, and Conductivity is defined as the measure of the ease at which an electric charge or heat can pass through a material. A conductor is a material which gives very little resistance to the flow of an electric current or thermal energy.

Resistivity $\rho$ of a material is related to its conductivity as $\rho \propto {\displaystyle \frac{1}{\sigma }}$ which implies that, greater the resistivity of a material lesser it’s conductivity and lesser the resistivity of a material greater its conductivity. So, in the above question we have the lowest resistivity of Silver which is equal to $1.6\times {10}^{-6}ohmcm$. Hence, as its resistivity is lowest among them, its conductivity will be largest among given materials which makes silver a best electrical conductor.

Hence, silver is the best electrical conductor due to its lowest resistivity among the given materials.

Note: A good conductor of electricity simply means those materials which allows the electricity to flow through them easily with minimum or negligible resistance called good conductors of electricity. After silver, Copper is also the best electrical conductor of electricity.