Question

E=3V
R=1,5r
U=?
am tezaaa..... spunetimi repede...

Answer 1

$R=1.5r\Rightarrow r=\frac{R}{1.5}=\frac{2}{3}R$
Aplicam legile lui Kirchoff pe intregul circuit
$E=I*(R+r)=I*(R+\frac{2}{3}R)=I*R*\frac{5}{3}$
Tensiunea electrica U are formula
$U=I*R$:Atunci
$E=\frac{5}{3}*U\Rightarrow U=\frac{3}{5}*E=9/5=1.8V$