Question

seja o circuito abaixo. determine:
a) a corrente em cada resistor
b) a corrente do circuito
c) a resistencia equivalente
d) a tensao de alimentacao: 220v

R1=10Ω    
R2=25Ω
R3=20Ω

A----------------------------------------------------/
              /                       /                          /
             R1                   R2                      R3
             /                       /                          /
B---------------------------------------------------/

Answer 1

Bom, vamos fazer então pelas informações dadas:

a) $U = R_{1} \cdot i_{1} \\\\ 220 = 10 \cdot i_{1} \\\\ i_{1} = \frac{220}{10} \\\\ \boxed{i_{1} = 22A} \\\\\\ U = R_{2} \cdot i_{2} \\\\ 220 = 25 \cdot i_{2} \\\\ i_{2} = \frac{220}{25} \\\\ \boxed{i_{2} = 8,8A} \\\\\\ U = R_{3} \cdot i_{3} \\\\ 220 = 20 \cdot i_{3} \\\\ i_{3} = \frac{220}{20} \\\\ \boxed{i_{3} = 11A}$



b) $i_{t} = i_{1}+i_{2}+i_{3} \\\\ i_{t} = 22+8,8+11 \\\\ \boxed{i_{t} = 41,8A}$


c) $\frac{1}{R_{eq.}} = \frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}} \\\\ \frac{1}{R_{eq.}} = \frac{1}{10}+\frac{1}{25}+\frac{1}{20} \\\\ MMC = 100 \\\\ \frac{1}{R_{eq.}} = \frac{10}{100}+\frac{4}{100}+\frac{5}{100} \\\\ \frac{1}{R_{eq.}} = \frac{19}{100} \\\\ \boxed{R_{eq.} = \frac{100}{19} \Omega}$