Quiz — 145.._Corrigé Ondes-1.pdf

Question 1 sur 10 20:00

[{"id":17619,"question":"Quelle est la relation entre la longueur d'onde λ, la fréquence f et la célérité v d'une onde ?","option_a":"v = λ × f","option_b":"f = v × λ","option_c":"λ = v \/ f","option_d":"v = f \/ λ","option_e":"","option_f":"","bonne_reponse":"a","explication":"La relation fondamentale est v = λ × f, où v est la célérité, λ la longueur d'onde et f la fréquence.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"v = λ × f\", \"b\": \"f = v × λ\", \"c\": \"λ = v \/ f\", \"d\": \"v = f ","_debug_options_count":4},{"id":17620,"question":"Une onde sonore est une onde mécanique longitudinale.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai : les ondes sonores sont des ondes mécaniques longitudinales, car la perturbation se fait dans la même direction que la propagation.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":17621,"question":"Quel phénomène se produit lorsque deux ondes de même fréquence et amplitude se superposent en phase ?","option_a":"Interférence destructive","option_b":"Interférence constructive","option_c":"Diffraction","option_d":"Réflexion","option_e":"","option_f":"","bonne_reponse":"b","explication":"L'interférence constructive se produit lorsque les ondes sont en phase, ce qui amplifie l'amplitude résultante.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Interférence destructive\", \"b\": \"Interférence constructive\", \"c","_debug_options_count":4},{"id":17622,"question":"La célérité d'une onde dépend-elle du milieu de propagation ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai : la célérité d'une onde dépend des propriétés du milieu (ex. : vitesse du son dans l'air vs. dans l'eau).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":17624,"question":"Quelle est l'unité SI de la fréquence ?","option_a":"Hertz (Hz)","option_b":"Mètre (m)","option_c":"Seconde (s)","option_d":"Newton (N)","option_e":"","option_f":"","bonne_reponse":"a","explication":"L'unité SI de la fréquence est le Hertz (Hz), équivalent à s⁻¹.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Hertz (Hz)\", \"b\": \"Mètre (m)\", \"c\": \"Seconde (s)\", \"d\": \"Newton ","_debug_options_count":4},{"id":17626,"question":"Une onde électromagnétique peut-elle se propager dans le vide ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai : les ondes électromagnétiques (comme la lumière) se propagent dans le vide, contrairement aux ondes mécaniques.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":17628,"question":"Quelle formule relie la période T et la fréquence f d'une onde ?","option_a":"T = 1 \/ f","option_b":"f = T²","option_c":"T = f","option_d":"f = 2πT","option_e":"","option_f":"","bonne_reponse":"a","explication":"La période T est l'inverse de la fréquence : T = 1 \/ f.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"T = 1 \/ f\", \"b\": \"f = T²\", \"c\": \"T = f\", \"d\": \"f = 2πT\"}}","_debug_options_count":4},{"id":17630,"question":"Le phénomène de diffraction est plus marqué lorsque la taille de l'obstacle est grande par rapport à la longueur d'onde.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Faux : la diffraction est plus marquée lorsque la taille de l'obstacle est \u003Cstrong\u003Epetite\u003C\/strong\u003E par rapport à la longueur d'onde.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":17632,"question":"Quelle est la célérité de la lumière dans le vide ?","option_a":"3 × 10⁸ m\/s","option_b":"340 m\/s","option_c":"1500 m\/s","option_d":"5000 m\/s","option_e":"","option_f":"","bonne_reponse":"a","explication":"La célérité de la lumière dans le vide est d'environ 3 × 10⁸ m\/s (300 000 km\/s).","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"3 × 10⁸ m\/s\", \"b\": \"340 m\/s\", \"c\": \"1500 m\/s\", \"d\": \"5000 m\/s\"","_debug_options_count":4},{"id":17634,"question":"Les ondes radio sont-elles des ondes électromagnétiques ?","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai : les ondes radio font partie du spectre électromagnétique, avec des fréquences comprises entre 3 kHz et 300 GHz.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4}]