Đáp án:
C
Giải thích các bước giải:
Ta có
\[\begin{array}{l}
R = \frac{{\rho L}}{s}\\
\frac{{{R_1}}}{{{R_2}}} = \frac{{{L_1}}}{{{L_2}}}.\frac{{{s_2}}}{{{s_1}}} = 1.\frac{{0,4}}{{0,2}} = 2
\end{array}\]
Mạch : \({R_1}//{R_2} \Rightarrow {U_1} = {U_2}\)
\[\begin{array}{l}
{I_1} = \frac{{{U_1}}}{{{R_1}}};{I_2} = \frac{{{U_2}}}{{{R_2}}}\\
\frac{{{I_1}}}{{{I_2}}} = \frac{{\frac{{{U_1}}}{{{R_1}}}}}{{\frac{{{U_2}}}{{{R_2}}}}} = \frac{{{R_2}}}{{{R_1}}} = \frac{1}{2} \Rightarrow {I_1} = \frac{1}{2}{I_2}
\end{array}\]
