Đáp án:
+\({R_2}//{R_3} \Rightarrow {R_{23}} = \dfrac{{{R_2}.{R_3}}}{{{R_2} + {R_3}}} = \dfrac{{150.100}}{{150 + 100}} = 60\Omega \)
+ \({R_1}nt{R_{23}} \Rightarrow {R_{123}} = {R_1} + {R_{23}} = 90 + 60 = 150\Omega \)
+\({R_5}//{R_6} \Rightarrow {R_{56}} = \dfrac{{{R_5}.{R_6}}}{{{R_5} + {R_6}}} = \dfrac{{100.100}}{{100 + 100}} = 50\Omega \)
+ \({R_4}nt{R_{56}} \Rightarrow {R_{456}} = {R_4} + {R_{56}} = 150 + 50 = 200\Omega \)
+\({R_{123}}//{R_{456}} \Rightarrow {R_{td}} = \dfrac{{{R_{123}}.{R_{456}}}}{{{R_{123}} + {R_{456}}}} = \dfrac{{150.200}}{{150 + 200}} = \dfrac{{600}}{7}\Omega \)
+ Cường độ dòng điện \(I = \dfrac{U}{{{R_{td}}}} = \dfrac{{240}}{{\dfrac{{600}}{7}}} = 2,8A\)
