Question

Ex 7 pagina 247 fizica

Answer 1

a) Prima data grupam R1 si R2 in serie:

Res=R1+R2

Res=12Ω

Acum grupam in paralel Res cu R3:

$\frac{1}{Rep}=\frac{1}{Res}+\frac{1}{R3}$

$\frac{1}{Rep}=\frac{1}{12}+\frac{1}{6}$

$\frac{1}{Rep}=\frac{3}{12}$

Rep=4Ω

b)$I2=\frac{U_{Res} }{Res}$⇒$U_{Res}=I2Res$⇒$U_{Res}$=8,4V

$U_{Res}=U_{R3}=U_{Rep}$=8,4Ω

I3=$\frac{U_{R3} }{R3}$⇒$I3=\frac{8,4}{6}$⇒I3=1,4A