Sơ đồ mắc: \(R_1 nt (R_2//R_3)\)
\(\Rightarrow R_{tđ}=R_1+\dfrac{R_2R_3}{R_2+R_3}=10+\dfrac{30\cdot60}{30+60}=30\left(\Omega\right)\)
\(\Rightarrow I=\dfrac{U}{R_{tđ}}=\dfrac{60}{30}=2\left(A\right)=I_1=I_{23}=I_{A_1}\)
\(\Rightarrow U_{23}=I_{23}R_{23}=2\left(30-10\right)=40\left(V\right)=U_2=U_3\)
\(\Rightarrow I_2=\dfrac{U_2}{R_2}=\dfrac{40}{30}=\dfrac{4}{3}\left(A\right)=I_{A_2}\)
\(\Rightarrow I_3=\dfrac{U_3}{R_3}=\dfrac{40}{60}=\dfrac{2}{3}\left(A\right)=I_{A_3}\)
Vậy \(I_{A_1}=2A;I_{A_2}=\dfrac{4}{3}A;I_{A_3}=\dfrac{2}{3}A\)


