Mobilities of electrons and holes in a sample of intrinsic germanium at room temperature are $0.36m^2 / Vs$ and $0.17m^2 / Vs$. The electron and hole densities are each equal to $2.5×10^{19}m^3$. The electrical conductivity of germanium is:
Answer & explanation
Correct answer: option 3
The electrical conductivity of germanium,
$σ=\frac{1}{ρ}=e(μ_en_e+μ_hn_h)$
$=(1.6×10^{-19})[0.36 0.17](2.5×10^{19})$
$=2.12 Sm^{-1}$