a, K mở
R14 = R1 + R4 = 6Ω
Tương tự, R23 = 7Ω
=> Rtd = \(\dfrac{R14.R23}{R14+R23}\) = \(\dfrac{6\cdot7}{6+7}\)= \(\dfrac{42}{13}\) A
=> I14 = \(\dfrac{U}{R14}\) = \(\dfrac{20}{6}\) A = I1 = I4
I23 = \(\dfrac{U}{R23}\) = \(\dfrac{20}{7}\) A = I2 = I3
b. K đóng
R12 = \(\dfrac{R1\cdot R2}{R1+R2}\) = \(\dfrac{2}{3}\)Ω ; Tương tự R34 = 2,4 Ω
=> Rtđ= R12 + R34 = \(\dfrac{46}{15}\) Ω
=> I = \(\dfrac{U}{Rtd}\) = \(\dfrac{150}{23}\) A = I12 = I34
=> U12 = I * R12 = \(\dfrac{100}{23}\) V ; Tương tự, U34 = \(\dfrac{360}{23}\) V
=> I1 = \(\dfrac{U12}{R1}\) = \(\dfrac{50}{23}\) A
Tương tự, I2 = \(\dfrac{100}{23}\) A
=> I3 = \(\dfrac{U34}{R3}\) = \(\dfrac{60}{23}\) A
Tương tự, I4 = \(\dfrac{90}{23}\) A
