Giúp t đik mm lololoooo

Đáp án:

\(\dfrac{{80}}{9}V\)

Giải thích các bước giải:

Mạch gồm: (R1 // R2) nt (R3 // R4)

Ta có:

\(\begin{array}{l}
{R_{12}} = \dfrac{{{R_1}{R_2}}}{{{R_1} + {R_2}}} = \dfrac{{40.10}}{{40 + 10}} = 8\Omega \\
{R_{34}} = \dfrac{{{R_3}{R_4}}}{{{R_3} + {R_4}}} = \dfrac{{20.20}}{{20 + 20}} = 10\Omega \\
I = \dfrac{U}{{{R_{12}} + {E_{34}}}} = \dfrac{{20}}{{8 + 10}} = \dfrac{{10}}{9}A\\
{U_1} = {U_2} = I.{R_{12}} = \dfrac{{10}}{9}.8 = \dfrac{{80}}{9}V\\
{U_3} = {U_4} = U - {U_1} = 20 - \dfrac{{80}}{9} = \dfrac{{100}}{9}V\\
{I_1} = \dfrac{{{U_1}}}{{{R_1}}} = \dfrac{{80}}{{9.40}} = \dfrac{2}{9}A\\
{I_2} = I - {I_1} = \dfrac{{10}}{9} - \dfrac{2}{9} = \dfrac{8}{9}A\\
{I_3} = \dfrac{{{U_3}}}{{{R_3}}} = \dfrac{{100}}{{9.20}} = \dfrac{5}{9}A\\
{I_4} = I - {I_3} = \dfrac{{10}}{9} - \dfrac{5}{9} = \dfrac{5}{9}A
\end{array}\)