Given, length of germanium rod, l=0.928cm =0.928×10−2m Area of cross-section, A=1mm2 Intrinsic charge carrier, ni=2.5×1019m−3, Mobility of hole, µh=0.15m2V−1s−1 and mobility of electron, µe=0.35m2V−1s−1 As we know that, Conductivity, σ=nie(µe+µh) =2.5×1019×1.6×10−19(0.15+0.35) =25×1.6×0.50 =4×0.5=2Ω−1m−1 Resistivity, ρ=