Respuesta :

In series circuit, Req = R₁ + R₂ + R₃ + ···

In parallel circuit, [tex]\frac{1}{Req}  = \frac{1}{R1} + \frac{1}{R2} + \frac{1}{R3} +...[/tex]

Q7.

total resistance in the upper branch = R₂ + R₃ = R₂ + 2

[tex]\frac{1}{Req} = \frac{1}{R2+R3} + \frac{1}{R1}[/tex]

[tex]\frac{1}{4} = \frac{1}{R2+2} +\frac{1}{6}[/tex]

R₂ + 2 = 12

R₂ = 10Ω

Q8.

[tex]\frac{1}{Req} = \frac{1}{R2+R3} + \frac{1}{R1}[/tex]

[tex]\frac{1}{Req} = \frac{1}{2+1} + \frac{1}{4}[/tex]

Req = 1.7Ω