Question

SI unit of conductivity is:

• A. $S{m}^{-1}$
• B. $S{s}^{-1}$
• C. $S{m}^1$
• D. None of these

Answer 1

The correct option is A

$S{m}^{-1}$

Explanation for the correct option

1. Any substance's ability to carry electricity through ions is measured by its conductivity, also known as specific conductance.
2. Electrical conductivity is the current or the quantity of electricity passing per second through a similar slab when the potential gradient is unity, and it is the reciprocal of the resistivity $\left(\rho \right)$
3. Conductivity is denoted by $\sigma$. Therefore $\sigma =\frac{1}{\rho }$ where $\rho =R\frac{A}{\mathcal{l}}$; $R$ is the Resistance of the electrical specimen of uniform material, $A$ is the cross-sectional area of the specimen and $\mathcal{l}$ is the length of the specimen.
4. In SI system, the unit Resistance is Ohm denoted as $\Omega$, the unit of Area is square meter denoted as $m^2$ and the unit of length is meter denoted as $m$. Therefore the unit of Resistivity $\left(\rho \right)$ is $\Omega \frac{m^2}{m}=\Omega m$
5. The SI unit of conductivity $\sigma$ is $\frac{1}{\Omega m}$ i.e. Siemens per meter and is denoted as $\raisebox{1ex}{$S$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$ or $S{m}^{-1}$

Hence, the correct option is option(A) i.e. $S{m}^{-1}$.