a) \(K_1\) đóng , \(K_2\) ngắt \(=>I_1=\dfrac{U}{R_1+R_4}=\dfrac{6}{2+12}=0,43\left(A\right)\)
b) \(K_1,K_2\) đều đóng \(=>R_{tđ}=R_1+\dfrac{1}{\dfrac{1}{R_2}+\dfrac{1}{R_3}+\dfrac{1}{R_4}}=4\Omega\)
\(=>I_1=\dfrac{U}{R_{tđ}}=1,5\left(A\right)\)
\(U_{432}=I_1\) . \(\dfrac{1}{\dfrac{1}{R_2}+\dfrac{1}{R_3}+\dfrac{1}{R_4}}=3\left(V\right)\)
\(=>I_2=\dfrac{U_{432}}{R_2}=0,75\left(A\right)\)
\(I_3=\dfrac{U_{432}}{R_3}=0,5\left(A\right)\)
\(I_4=\dfrac{U_{432}}{R_4}=0,25\left(A\right)\)