来自彭晗的问题
如图所示的电路中,当开关S闭合,甲、乙两表为电压表时,两表读数之比U甲:U乙为3:1当开关S断开,甲、乙两表为电流表时,两表的读数之比I甲:I乙为.A.2:1B.2:3C.3:1D.3:2
如图所示的电路中,当开关S闭合,甲、乙两表为电压表时,两表读数之比U甲:U乙为3:1当开关S断开,甲、乙两表为电流表时,两表的读数之比I甲:I乙为.
A.2:1
B.2:3
C.3:1
D.3:2


如图所示的电路中,当开关S闭合,甲、乙两表为电压表时,两表读数之比U甲:U乙为3:1当开关S断开,甲、乙两表为电流表时,两表的读数之比I甲:I乙为.A.2:1B.2:3C.3:1D.3:2
如图所示的电路中,当开关S闭合,甲、乙两表为电压表时,两表读数之比U甲:U乙为3:1当开关S断开,甲、乙两表为电流表时,两表的读数之比I甲:I乙为.
A.2:1
B.2:3
C.3:1
D.3:2
若甲、乙均为电压表时,闭合开关S,R1和R2串联,U=U甲,U2=U乙,由题知,U甲:U乙=3:1,即:U:U2=3:1,∴U1:U2=2:1,∵U1R1=U2R2,∴R1:R2=U1:U2=2:1;若甲、乙均为电流表时,断开开关S,R1和R2并联,I1:I2...