接0-3V,为串联的R 1,则R 1=
U 1
I g -R g=
3
3 ×10 -3 -100=900Ω
接0-15V时,为串联的R 1和R 2,则R 2=
U 2
I g -R g-R 1=4000Ω
故答案为:900,4000.