Question

am nevoe de ajutor !!!

Answer 1

Se da:
R1=4Ω
R2=2Ω
R3=1Ω
r=0,2Ω
E=12V
a)R=?Ω
b)I=?A

Formule:
a)R=R12+R3

1/R12=1/R1+1/R2
1/R12=(R1+R2)/R1R2
R12=R1R2/(R1+R2)

R=R1R2/(R1+R2)+R3

b)I=E/(R+r)

Calcule:
a)R=4*2/(4+2)+1=2,(3)Ω
b)I=12/[2,(3)+0,2]≈4,74A