A、1/R=(1/R1)+(1/R2)+(1/R3) B、R=R1+R2+R3 C、R=1/(R1R2R3) D、R=R1=R2=R3
A、U=(1/U1)+(1/U2)+(1/U3) B、U=U1U2U3 C、U=U1+U2+U3 D、U=U1=U2=U3
A、R=R1=R2=R3 B、R=R1+R2+R3 C、1/R=1/R1+1/R2+1/R3 D、R=R1R2R3