a. \(R=R1+\left(\dfrac{R2.R3}{R2+R3}\right)=30+\left(\dfrac{15.10}{15+10}\right)=36\Omega\)
b. \(I=I1=I23=U:R=24:36=\dfrac{2}{3}A\left(R1ntR23\right)\)
\(U23=U2=U3=U-U1=24-\left(30.\dfrac{2}{3}\right)=4V\)(R2//R3)
\(\Rightarrow\left\{{}\begin{matrix}I2=U2:R2=4:15=\dfrac{4}{15}A\\I3=U3:R3=4:10=0,4A\end{matrix}\right.\)
c. \(5p=\dfrac{1}{12}h\)
\(A=UIt=24.\dfrac{2}{3}.\dfrac{1}{12}=\dfrac{4}{3}\left(Wh\right)\)
\(R_1nt\left(R_2//R_3\right)\)
a) \(R_{tđ}=R_1+\dfrac{R_2\cdot R_3}{R_2+R_3}=30+\dfrac{15\cdot10}{15+10}=36\Omega\)
b) \(I_1=I_{23}=I_m=\dfrac{U}{R}=\dfrac{24}{36}=\dfrac{2}{3}A\)
\(U_2=U_3=U_{23}=\dfrac{2}{3}\cdot6=4V\)
\(I_2=\dfrac{4}{15}A\)
\(I_3=\dfrac{4}{10}=0,4A\)
c) Công đoạn mạch sinh ra trong 5 phút=300s là:
\(A=U_{AB}\cdot I_{AB}\cdot t=24\cdot\dfrac{2}{3}\cdot300=4800J\)
