*Mạch nt:
Sđmđ: R1 nt R2 nt R3
⇒Rtđ=R1+R2+R3=2+3+6=11 ôm
Ta có: $I_{mc}$=$I_{1}$=$I_{2}$=$I_{3}$ =$\frac{U_{AB}}{R_{tđ}}$=$\frac{12}{11}$(A)
*Mạch //:
Sđmđ: R1//R2//R3
⇒Rtđ=$\frac{1}{R1}$ +$\frac{1}{R2}$ +$\frac{1}{R3}$ =$\frac{1}{2}$ +$\frac{1}{3}$ +$\frac{1}{6}$ =1 ôm
Ta có: $U_{AB}$=$U_{1}$=$U_{2}$=$U_{3}$=12(V)
⇒$I_{1}$=$\frac{U_{1}}{R_{1}}$ =$\frac{12}{2}$ =6(A)
⇒$I_{2}$=$\frac{U_{2}}{R_{2}}$ =$\frac{12}{3}$ =4(A)
⇒$I_{3}$=$\frac{U_{3}}{R_{3}}$ =$\frac{12}{6}$ =2(A)
