108

De spanning over R2 is:

a   40 V
b   60 V
c  100 V
d   80 V

R3 en R2 parallel
Rv = 1/(1/R3+1/R2) = 1/(1/60+1/20) = 15 Ω
Rt = Rv+R1 = 60 + 15 = 75 Ω
I = U / Rt = 100 / 75 = 1.3 A
UR1 = I * R1 = 1.3 * 60 = 80 V
Over  Rv = 20 V
I2 = U2 / R2 = 20/20 = 1A

R1 en R2 parallel
RV = 1/(1/R1+1/R2) = 1/(1/60+1/20) = 15 Ω
Rt = Rv+R1 = 60 + 15 = 75 Ω
I = U / Rt = 100 / 75 = 1.3 A
UR3 = I * R3 = 1.3 * 60 = 80 V
Over  Rv = 20 V
I2 = U2 / R2 = 20/20 = 1A

U = I * R = 2 * 20 = 40 V

OF

03

┘

┘