Question

两电阻R1,R2串联侯接在电压恒为24V的电路上,用一电压表表并联在R1两端时,示数为6V并联在R2时示数为12V

Answer 1

设电压表阻值为R,根据串联电流相等关系得：

6/R+6/R1=(24-6)/R2

12/R+12/R2=(24-12)/R1

得：1/R+1/R1=3/R2

1/R+1/R2=1/R1

得：3/R2-1/R1=1/R1-1/R2

4/R2=2/R1

R1/R2=1/2