Question

Urgent Puuncte * Coroana la fizica va rog mult

Answer 1

   
[tex]\displaystyle \\ \texttt{Se da :} \\ t = 20 ~s \\ I = 2~mA = 0,002~A\\ Q = 8~J \\ \texttt{Se cere :} \\ R = ? \\ \\ \texttt{Rezolvare: } \\ \\ P = \frac{Q}{t} = \frac{8}{20} J/s = 0,4~J/s =\boxed{ 0,4~W }\\ \\ P = U \times I \\ \\ U = \frac{P}{I} = \frac{0,4}{0,002} = \frac{400}{2} = \boxed{200 ~V} \\ \\ R = \frac{U}{I} = \frac{200}{0,002} = \frac{200000}{2} = 100000~ \Omega = \boxed{\boxed{100~K\Omega}}[/tex]