如图所示,电源电压恒定,当S接a时.电流表A1与A2的示数之比为3:5:当S接b时,电流表A1与A2的示数之比为2:3,则R2与R3的电阻之比为_______.
如图所示,电源电压恒定,当S接a时.电流表A1与A2的示数之比为3:5:当S接b时,电流表A1与A2的示数之比为2:3,则R2与R3的电阻之比为_______.
当S接a时,I1:I2=3:2,所以R1:R2=2:3,所以R2=3/2R1
当S接b时,I1:I3=2:1,所以R1:R3=1:2,所以R3=2R1
所以R2:R3=3/2R1:2R1=3:4