Find the current produces at room temperature  in pure germanium rod  of area 4×10−4m2  and thickness  2.4×10−3m. When the potential of  5V  is applied across  the faces. The concentration of  charge carriers with  germanium at room temperature  at  3.2×106  per  cubic metre.  The mobility of electron and hole  are 0.8m2v−1s−1  and  0.4m2v−1s−1 respectively.