Question 64: Current Electricity

Question

The SI unit of electrical conductivity is :

Accepted Answer

The correct option is C, $$\mathrm{S} \mathrm{~m}^{-1}$$.
Electrical conductivity is a measure of the ability of a material to conduct electric current. The SI unit of electrical conductivity is the siemens per meter ($$\mathrm{S} \mathrm{~m}^{-1}$$). It is the inverse of electrical resistivity (with resistivity measured in ohm-meters, $$\Omega \mathrm{~m}$$), and thus conductivity is expressed as the reciprocal of resistivity. Therefore, the formula to calculate conductivity ($\sigma$) from resistivity ($\rho$) is:
$$\sigma = \frac{1}{\rho}$$
So, when resistivity is in $$\Omega \mathrm{~m}$$, conductivity is given in $$\mathrm{S} \mathrm{~m}^{-1}$$, making option C the correct answer. The other units mentioned are related to electrical terms but do not correctly represent the unit of electrical conductivity:
Option A: "S m" is not properly formatted; it lacks the exponent to denote per meter.
Option B: $$\Omega \mathrm{~m}$$ is the unit of electrical resistivity, not conductivity.
Option D: $$\Omega \mathrm{~m}^{-1}$$ is not a standard unit for any electrical property.

Answer

S m

Answer

$$\Omega \mathrm{~m}$$

Answer

$$\mathrm{S} \mathrm{~m}^{-1}$$

Answer

$$\Omega \mathrm{~m}^{-1}$$

Current Electricity

The SI unit of electrical conductivity is :

Choose the correct answer: