Question

va rog ma puteti ajuta repede? ​

Answer 1

$R=50 \ \Omega \\ I=7 \ mA=0,007 \ A \\ I=\frac{U}{R} \ \Rightarrow \ U=I\cdot R=0,007 \ A \cdot 50 \ \Omega \\ \Rightarrow \ \boxed{U=0,35 \ V}$