The length of germanium rod is 1 cm and its area of cross-section is 1mm2. If for germanium ni=2.5×1019m−3 , μe=0.39m2v−1s−1 , μh=0.19m2v−1s−1. Its resistance in ohms is
Resistance = R=ρlA=lnieμe+μhA
=1×10−22.5×1019×1.6×10−190.39+0.19×10−6
=4310.34 Ω