Question

Giúp mk vs ạ :"(

Answer 1

\(R_1nt\left[\left(R_2ntR_3\right)//R_4\right]\)

\(R_{23}=R_2+R_3=2+2=4\Omega\)

\(R_{234}=\dfrac{R_{23}\cdot R_4}{R_{23}+R_4}=\dfrac{4\cdot4}{4+4}=2\Omega\)

\(R_{tđ}=R_1+R_{234}=1+2=3\Omega\)

a)\(I=\dfrac{U}{R_{tđ}}=\dfrac{12}{3}=4A\)

\(I_1=I_{mạch}=4A\Rightarrow U_1=I_1\cdot R_1=4\cdot1=4V\)

\(U_{23}=U_4=U_{234}=U-U_1=12-4=8V\)

\(I_{23}=I_2=I_3=\dfrac{U_{23}}{R_{23}}=\dfrac{8}{4}=2A\)

\(I_4=I-I_{23}=4-2=2A\)

b)\(U_{MN}=U_2=I_2\cdot R_2=2\cdot2=4V\)