Đáp án:
\(\begin{array}{l}
4.2.\\
{I_1} = \dfrac{3}{{{R_1}}}\\
{I_2} = \dfrac{{{U_2}}}{{1,5{R_2}}}\\
4.3.\\
I = {I_1} = {I_2}\\
4.4{U_2} = 4,5V
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
4.1\\
{R_1}nt{R_2}\\
{R_2} = 1,5{R_1}\\
{U_1} = 3V\\
- - - - - - - - - - - - - - \\
U = ?\\
4.2.\\
{I_1} = \dfrac{{{U_1}}}{{{R_1}}} = \dfrac{3}{{{R_1}}}\\
{I_2} = \dfrac{{{U_2}}}{{{R_2}}} = \dfrac{{{U_2}}}{{1,5{R_2}}}\\
4.3.\\
I = {I_1} = {I_2}\\
4.4\\
{I_1} = {I_2}\\
\Rightarrow \dfrac{3}{{{R_1}}} = \dfrac{{{U_2}}}{{1,5{R_2}}}\\
\Rightarrow {U_2} = 3.1,5 = 4,5V\\
\end{array}\)
