Question

  giải giúp e bài 1 với ạ

Answer 1

\(MCD:\left(R_1//R_2\right)ntR_3\)

\(\Rightarrow R=\dfrac{R_1R_2}{R_1+R_2}+R_3=\dfrac{10\cdot20}{10+20}+10=\dfrac{50}{3}\Omega\)

\(\rightarrow I=I_{12}=I_3=\dfrac{U}{R}=\dfrac{30}{\dfrac{50}{3}}=1,8A\)

\(\rightarrow U_3=I_3R_3=1,8\cdot10=18V\)

\(\rightarrow U_{12}=U_1=U_2=U-U_3=30-18=12V\)

\(\rightarrow\left\{{}\begin{matrix}I_1=\dfrac{U_1}{R_1}=\dfrac{12}{10}=1,2A\\I_2=\dfrac{U_2}{R_2}=\dfrac{12}{20}=0,6A\end{matrix}\right.\)