Respostas

A melhor resposta!
2014-07-28T19:51:57-03:00
U = R2 * i
6 = R2 * 0,30
R2 = 20 Ohms

R1= R2/3
R1 = 20/3 Ohms

Req = R1*R2/R1+R2
Req = (20*20/3) / (20+20/3)
Req = 400/3 / 80 / 3
Req = 400/3 * 3/80
Req = 400/80

Req = 5 Ohms

Achando o valor de R

U = Req * i
6 = 5 * i
6/5 = i


i = 1,2 A

U = R * i
6 = R * 1,2
6/1.2 = R

R = 5 Ohms

Alternativa C
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20 4 20