[tex]\displaystyle \\
Notatii: \\
U_{em} = 5V\\
U_{R_c} = 4V \\R_c = Rezistenta ~circuitului~ exterior \\
R_i = Rezistenta ~interna~a~ bateriei \\
Rezolvare: \\
\texttt{Aplicam legea lui Ohm: } R= \frac{U}{I} \\ \\
(Ri + Rc) = \frac{Uem}{I} =\frac{5V}{1A}= \boxed{5\Omega} \\ \\
R_c = \frac{U_{R_c} }{I} =\frac{4V}{1A}= \boxed{4\Omega }\\ \\
R_i = (Ri + Rc) - R_c = 5\Omega - 4\Omega = \boxed{1 \Omega } [/tex]