a) as it is
I1 = 200/(20+10//10) = 8,0 A
I2 = I3 = I1/2 = 4,0 A
P1 = 8^2*20 = 1280 w
P2 = P3 = 4^2*10 = 160 w
Pg = P1+P2+P3 = 1600 w
b) R1 = 0
I1 = 200/(10//10) = 40 A
P2 = P3 = 40^2*10 = 16.000 w
Pg = P2+P3 = 32.000 w
c) R2 ed R3 = 0
I1 = 200/20 = 10 A
Pg = P1 = 10^2*20 =2.000 w
d) corto circuito : Ig ⇒ ∞
e) R3 = ∞
I1 = 200/30 = 20/3 di A
P1 = 400/9*20 = 8000/9 w
P2 = P1/2 = 4000/9 w
Pg = P1+P2 = 4000/3 w
f) R2 = ∞
I1 = 200/30 = 20/3 di A
P1 = 400/9*20 = 8000/9 w
P3 = P1/2 = 4000/9 w
Pg = P1+P3 = 4000/3 w