Question

The polarisability of a given material is 1.0×10^-40 C^2 mN^−1 . Determine its dielectric constant if the number of molecules in 1 m^3 volume of the material is 5.0×10^25.

Answer 1

According to the Clausius-Mosotti equation

$\frac{\epsilon-1}{\epsilon+2} = 1.33\pi N\alpha = 1.33\cdot 3.14\cdot 5\cdot10^{25}10^{-37}$

then $\epsilon$ $=1 + 3\cdot 2.110^{-11} = 1+ 6.3 \cdot 10^{-11}$