解：S=20×80mm2=1.6×103m2 1=2.0m △U=50mV=5.0×10-2V y=5.7×107S p=1.36×101C/m3 R- 1 2.0 5.7×107×1.6×103=2.19×1052) I △U5.0×102 R-2.19×105=2.28×103(A 6= I2.28×103 =1.6×103=1.43×10(A/m2) S E= ΔU5.0×102 2.0 =2.5×102(V/m 结束目录 解： S =20×80mm2 =1.6×10-3m2 l =2.0m DU =50mV =5.0×10-2V g =5.7×107 S r =1.36×1010C/m3 R S l = g = 2.0 5.7×107×1.6×10-3 =2.19×10-5 (W) I = DU R = 5.0×10-2 2.19×10-5 =2.28×103 (A) δ I = S = 2.28×103 1.6×10-3 =1.43×106 (A/m2 ) E = DU l = 2.0 5.0×10-2 =2.5×10-2 (V/m) 结束 目录