Question

Cho R1 nt [(R2//R3)//R5] nt R4. R1=R2= 4Ohm, R3= 6Ohm, R4= 3Ohm, R5= 10Ohm,UAB=24V. Tính Rtd của đoạn mạch AB và hiệu điện thế qua mỗi điện trở.

Answer 1

\(MCD:R_1nt\left[\left(R_2//R_3\right)//R_5\right]ntR_4\)

\(\Rightarrow R_{td}=R_1+R_{235}+R_4=4+\dfrac{\left(\dfrac{4\cdot6}{4+6}\right)\cdot10}{\left(\dfrac{4\cdot6}{4+6}\right)+10}+3=\dfrac{277}{31}\Omega\)

\(\Rightarrow I=I_1=I_{235}=I_4=\dfrac{U}{R_{td}}=\dfrac{24}{\dfrac{277}{31}}=\dfrac{744}{277}A\)

\(\Rightarrow U_1=I_1\cdot R_1=\dfrac{744}{277}\cdot4=\dfrac{2976}{277}V\)

\(\Rightarrow U_{235}=U_{23}=U_2=U_3=U_5=I_{235}\cdot R_{235}=\dfrac{744}{277}\cdot\dfrac{\left(\dfrac{4\cdot6}{4+6}\right)\cdot10}{\left(\dfrac{4\cdot6}{4+6}\right)+10}=\dfrac{1440}{277}V\)

\(\Rightarrow U_4=I_4\cdot R_4=\dfrac{744}{277}\cdot3=\dfrac{2232}{277}V\)