1)
电流表两端电压Ug=Ig*Rg=0.003*120=0.36V
串联电阻R1两端电压U1=U-Ug=6-0.36=5.64V
R1和Rg等电流
R1=U1/Ig=5.64/0.003=1880Ω
改装后电压表的内阻R=Rg+R1=2000Ω
2)
并联R2分流
过R2电流I2=3A-3mA=2.997A
R2和Rg等电压
R2=Ug/I2=0.12Ω
1)
电流表两端电压Ug=Ig*Rg=0.003*120=0.36V
串联电阻R1两端电压U1=U-Ug=6-0.36=5.64V
R1和Rg等电流
R1=U1/Ig=5.64/0.003=1880Ω
改装后电压表的内阻R=Rg+R1=2000Ω
2)
并联R2分流
过R2电流I2=3A-3mA=2.997A
R2和Rg等电压
R2=Ug/I2=0.12Ω