Question

Answer 1

CTM: \(\left(R_1ntR_3\right)//\left(R_2ntR_4\right)\)

\(R_{13}=R_1+R_3=2+6=8\Omega\)

\(R_{24}=R_2+R_4=8+16=24\Omega\)

\(R_{tđ}=\dfrac{R_{13}\cdot R_{24}}{R_{13}+R_{24}}=\dfrac{8\cdot24}{8+24}=6\Omega\)

\(I=\dfrac{\xi}{R_N+r}=\dfrac{48}{6+0}=8A\)

\(U_{MN}=U_N-U_M=U_1-U_2\)

Khi \(r=0\Rightarrow U_N=\xi=48V\Rightarrow\)\(U_{13}=U_{24}=U=48V\)

\(I_1=I_3=I_{13}=\dfrac{U_{13}}{R_{13}}=\dfrac{48}{8}=6A\Rightarrow U_1=I_1\cdot R_1=12V\)

\(I_2=I_4=I_{24}=\dfrac{U_{24}}{R_{24}}=\dfrac{48}{24}=2A\Rightarrow U_2=I_2\cdot R_2=2\cdot8=16V\)

\(\Rightarrow U_{MN}=U_1-U_2=12-16=-4V\)