ELECTROTÉCNIA

KIRCHOFF

=208·230-[-140·(140)]= 28240

I1=[(0·230)-(-140·10)]/28240= 49 mA

I2=[(280·10)-(-140·0)]/28240= 73 mA

I2=Ir3

Vr3= Ir3·R3 73·68= 4'9V

THEVENIN

Vth= (E1-E2)·[R2/(R1+R2)]+E2

(10-10)·[140/(140+68)]+10= 10V

Rth= R1·R2/R1+R2

140·68/140+68= 45'79

Rth'=R3·R4/R3+R4

68·22/68+22= 16'62

I1= Vth/(Rth- Rth') 10/(45'79-16'62)= 34 mA

I2= Vth/(Rth+R3+R4) 10/(45'79+68+22)= 79 mA

I2=Ir3

Vr3= Ir3·R3 73·68= 4'9V

R1