a. R1nt[(R2ntR3)//R4)
RCDB=R2+R3=6+4=10Ω
RCB=\(\dfrac{RCDB.R4}{RCDB+R4}=\dfrac{10.10}{10+10}=5\)Ω
Rtđ=R1+RCB=2+5=7Ω
b.I=I1=\(\dfrac{U}{Rtđ}=\dfrac{28}{7}=4A\)
U4=UCB=ICB.RCB=I.RCB=4.5=20V
I4=\(\dfrac{U4}{R4}=\dfrac{UCD}{R4}=\dfrac{20}{10}=2A\)
I2=I3=I-I4=4-2=2A