Đáp án:
\(\begin{array}{l}
A.{R_1} = 24\Omega \\
,{R_2} = 12\Omega
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
+ nt\\
{R_{nt}} = {R_1} + {R_2}\\
{P_{nt}} = \dfrac{{{U^2}}}{{{R_{nt}}}} \Rightarrow 4 = \dfrac{{{{12}^2}}}{{{R_{nt}}}}\\
\Rightarrow {R_{nt}} = {R_1} + {R_2} = 36(1)\\
+ //\\
{P_{//}} = \dfrac{{{U^2}}}{{{R_{//}}}} \Rightarrow 18 = \dfrac{{{{12}^2}}}{{{R_{//}}}}\\
\Rightarrow {R_{//}} = 8\\
\Rightarrow \dfrac{1}{{{R_{//}}}} = \dfrac{1}{{{R_1}}} + \dfrac{1}{{{R_2}}} = \dfrac{1}{8}(2)\\
(1),(2) \Rightarrow \left\{ \begin{array}{l}
{R_1} = 24\Omega \\
{R_2} = 12\Omega
\end{array} \right.
\end{array}\)