A.待测的干电池一节
B.电流表A1(量程0~3mA,内阻Rg1=10Ω)
C.电流表A2(量程0~0.6A,内阻Rg2=0.1Ω)
D.滑动变阻器R1(0~20Ω,1.0A)
E.电阻箱R0(0~9999.9Ω)
F.开关和若干导线