Решить: дано: е2=25в, е3=4в, r1=6 ом, r3=2 oм, r4=3 0m, r5=8 om, r1=2 om, r2=8 om

4)

R23 = 20 + 30 = 50 Ом

R45 = 15 + 35 = 50 Ом

1/R2345 = 1/R23 + 1/R45

1/R2345 = 1/50 + 1/50 = 1/25

R2345 = 25 Ом

R123456 = 10 + 25 + 50 = 85 Ом.

5)

R = U/I = 120 / 1,5 = 80 Ом

R = pl / S

80 = 0,14 * 200 / S

80 = 28 / S

S = 28/80 = 0,35 м2.

6)

1/R23 = 1/R2 + 1/R3

1/R23 = 1/10 + 1/10 = 1/5

R23 = 5 Ом

R1234 = 2 + 5 + 3 = 10 Ом

I = U/R = 10 / 10 = 1 А.