Bài 1:
a. \(R=\dfrac{R1.R2}{R1+R2}=\dfrac{3.6}{3+6}=2\left(\Omega\right)\)
b. \(U=U1=U2=9V\)(R1//R2)
\(\Rightarrow\left\{{}\begin{matrix}I=\dfrac{U}{R}=\dfrac{9}{2}=4,5\left(A\right)\\I1=\dfrac{U1}{R1}=\dfrac{9}{3}=2\left(A\right)\\I2=\dfrac{U2}{R2}=\dfrac{9}{6}=2,5\left(A\right)\end{matrix}\right.\)
Bài 2:
a. \(R=R1+R2+R3=6+12+24=42\left(\Omega\right)\)
b. \(I=I1=I2=\dfrac{U}{R}=\dfrac{63}{42}=1,5\left(A\right)\left(R1ntR2ntR3\right)\)
\(\Rightarrow\left\{{}\begin{matrix}U1=I1.R1=1,5.6=9\left(V\right)\\U2=I2.R2=1,5.12=18\left(V\right)\\U3=I3.R3=1,5.24=36\left(V\right)\end{matrix}\right.\)
