[ V_C(t) = E + A e^-t/RC ]
[ \boxedV_C(t) = E \left(1 - e^-t/\tau\right) \quad \textfor \quad 0 \leq t \leq t_1 ] where ( \tau = RC ). 2.2 Calcul de la constante de temps (Time constant) [ \tau = R \cdot C = (1 \times 10^3) \cdot (100 \times 10^-6) = 10^3 \cdot 10^-4 = 0.1 \ \texts ]
Initial condition at ( t = t_1^+ ): ( V_C(t_1) = 9.93 \text V ) (continuity of capacitor voltage). exercice corrige electrocinetique
With ( i(t) = C \fracdV_Cdt ), we get:
[ \boxed\tau = 100 \ \textms ] At ( t_1 = 0.5 \ \texts ): [ V_C(t) = E + A e^-t/RC ]
[ RC \fracdV_Cdt + V_C = E ]
[ E = V_R(t) + V_C(t) = R i(t) + V_C(t) ] The source is disconnected, and the capacitor discharges
Initial condition ( V_C(0) = 0 ): [ 0 = E + A \quad \Rightarrow \quad A = -E ]
Solution:
[ V_C(t_1) = 10 \left(1 - e^-5\right) \approx 10 (1 - 0.0067) \approx 9.93 \ \textV ] The capacitor is almost fully charged. The source is disconnected, and the capacitor discharges through ( R ). The differential equation becomes:
[ V_C(t) = B e^-(t - t_1)/\tau ]