A.电流表A1(量程为3mA,)
B.电流表A2(量程为300mA,)
C.电压表V(量程为6V,内阻)
D.可变电阻R1:电阻箱(阻值可调范围0~9999Ω)
E.可变电阻R2:滑动变阻器(阻值变化范围0~10Ω)