View attachment 77492giúp mình bài 3,4,5 với
Bài 3
a) [tex](R_{1}//R_{2})nt R_{3}\Leftrightarrow R_{tđ}=R_{12}+R_{3}=\frac{R_{1}R_{2}}{R_{1}+R_{2}}+R_{3}=...[/tex]
B)[tex]I_{3}=I_{12}=I=\frac{U}{I}=...[/tex]
[tex]\Rightarrow U_{3}=I_{3}R_{3}=...[/tex] [tex]\Rightarrow U_{1}=U_{2}=U_{12}=U-U_{3}=....[/tex]
[tex]\Rightarrow I_{1}=\frac{U_{1}}{R_{1}}=....;I_{2}=\frac{U_{2}}{R_{2}}=....[/tex]