Tóm tắt:
R1 = 30
R2 = 20
R3 = 10
U = 120V
a)Ta có:
$R_{23}$=$\frac{R2.R3}{R2+R3}$
⇔$R_{23}$=$\frac{20.10}{20+10}$
⇔$R_{23}$= $\frac{20}{3}$ (ʊ)
⇒Rtđ=$R_{1}$+$R_{23}$=$\frac{110}{3}$ (ʊ)
b)Ta có:
I=I1=I23=$\frac{U}{R}$ =$\frac{120}{110/3}$=$\frac{36}{11}$(A)
⇒U1=I1.R1=$\frac{36}{11}$.30=$\frac{1080}{11}$(V)
U2=U3=U23=I23.R23=$\frac{240}{11}$(V)
⇒I2=$\frac{U2}{R2}$ =$\frac{240}{11}$: 20=$\frac{12}{11}$ (A)
⇒I3=$\frac{U3}{R3}$=$\frac{240}{11}$: 10=$\frac{24}{11}$(A)
→→Xin hay nhất←←
ThAnKs
