Circuit RLC forcé : Impédance, Résonance et Puissance

Question 1 sur 10 10:00

[{"id":48981,"question":"Dans un circuit RLC série, l'impédance Z est donnée par :","option_a":"Z = R + j(Lω + 1\/(Cω))","option_b":"Z = R + j(Lω - 1\/(Cω))","option_c":"Z = R - j(Lω - 1\/(Cω))","option_d":"Z = R - j(Lω + 1\/(Cω))","option_e":"","option_f":"","bonne_reponse":"B","explication":"L'impédance complexe d'un circuit RLC série est Z = R + j(Lω - 1\/(Cω)), où j est l'unité imaginaire.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48982,"question":"La fréquence de résonance d'un circuit RLC est donnée par :","option_a":"f₀ = 1\/(2π√(LC))","option_b":"f₀ = 1\/(2π√(RC))","option_c":"f₀ = 1\/(2π√(RL))","option_d":"f₀ = 1\/(2π(L + C))","option_e":"","option_f":"","bonne_reponse":"A","explication":"La fréquence de résonance est f₀ = 1\/(2π√(LC)), où L est l'inductance et C la capacité.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48983,"question":"À la résonance, le déphasage φ entre la tension et le courant est :","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"À la résonance, le déphasage φ est nul car l'impédance est purement résistive (Z = R).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48984,"question":"Le facteur de qualité Q d'un circuit RLC est défini par :","option_a":"Q = ω₀L\/R","option_b":"Q = R\/(ω₀L)","option_c":"Q = ω₀C\/R","option_d":"Q = R\/(ω₀C)","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le facteur de qualité est Q = ω₀L\/R, où ω₀ est la pulsation de résonance et R la résistance.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48985,"question":"La puissance moyenne dissipée dans un circuit RLC forcé est maximale :","option_a":"À la résonance","option_b":"Pour une fréquence nulle","option_c":"Pour une fréquence infinie","option_d":"Indépendamment de la fréquence","option_e":"","option_f":"","bonne_reponse":"A","explication":"La puissance moyenne est maximale à la résonance car l'impédance est minimale (Z = R).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48986,"question":"L'amplitude du courant dans un circuit RLC forcé est donnée par :","option_a":"I₀ = U₀ \/ Z","option_b":"I₀ = U₀ * Z","option_c":"I₀ = Z \/ U₀","option_d":"I₀ = U₀ + Z","option_e":"","option_f":"","bonne_reponse":"A","explication":"L'amplitude du courant est I₀ = U₀ \/ Z, où U₀ est l'amplitude de la tension et Z l'impédance.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48987,"question":"Le déphasage φ entre la tension et le courant est donné par :","option_a":"φ = arctan((Lω - 1\/(Cω))\/R)","option_b":"φ = arctan(R\/(Lω - 1\/(Cω)))","option_c":"φ = arctan((Lω + 1\/(Cω))\/R)","option_d":"φ = arctan(R\/(Lω + 1\/(Cω)))","option_e":"","option_f":"","bonne_reponse":"A","explication":"Le déphasage est φ = arctan((Lω - 1\/(Cω))\/R), où ω est la pulsation du signal.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48988,"question":"Un circuit RLC est dit 'sous-amorti' si :","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"Un circuit RLC est sous-amorti si le facteur d'amortissement ζ \u003C 1, ce qui correspond à des oscillations.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48989,"question":"La bande passante d'un circuit RLC est définie par :","option_a":"Δf = f₀ \/ Q","option_b":"Δf = Q \/ f₀","option_c":"Δf = f₀ * Q","option_d":"Δf = 1 \/ (f₀ * Q)","option_e":"","option_f":"","bonne_reponse":"A","explication":"La bande passante est Δf = f₀ \/ Q, où f₀ est la fréquence de résonance et Q le facteur de qualité.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0},{"id":48990,"question":"Pour un circuit RLC série, l'impédance est minimale :","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"B","explication":"L'impédance est minimale à la résonance car la partie réactive (Lω - 1\/(Cω)) s'annule.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0}]