Quiz — 148.._COURS ONDE + COR EX 1 SERIE 1 25.02.2020.pdf

Question 1 sur 10 20:00

[{"id":25564,"question":"Quelle grandeur physique reste inchangée lors de la réflexion d'une onde sur un obstacle ?","option_a":"La fréquence","option_b":"L'amplitude","option_c":"La vitesse de propagation","option_d":"La longueur d'onde","option_e":"","option_f":"","bonne_reponse":"a","explication":"La fréquence d'une onde est déterminée par la source et ne change pas lors de la réflexion.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"La fréquence\", \"b\": \"L'amplitude\", \"c\": \"La vitesse de propagati","_debug_options_count":4},{"id":25565,"question":"Une onde sonore se propage plus rapidement dans l'air que dans l'eau.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La vitesse du son est plus élevée dans les milieux denses comme l'eau que dans l'air.","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":25566,"question":"Quelle est la relation entre la longueur d'onde λ, la fréquence f et la vitesse v d'une onde ?","option_a":"λ = v × f","option_b":"v = λ × f","option_c":"f = v × λ","option_d":"λ = v \/ f","option_e":"","option_f":"","bonne_reponse":"b","explication":"La formule correcte est v = λ × f, où v est la vitesse, 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\": \"b\", \"options\": {\"a\": \"λ = v × f\", \"b\": \"v = λ × f\", \"c\": \"f = v × λ\", \"d\": \"λ = ","_debug_options_count":4},{"id":25567,"question":"Quel phénomène explique la formation d'un écho ?","option_a":"La diffraction","option_b":"La réflexion","option_c":"La réfraction","option_d":"L'absorption","option_e":"","option_f":"","bonne_reponse":"b","explication":"L'écho est dû à la réflexion des ondes sonores sur un obstacle distant.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"La diffraction\", \"b\": \"La réflexion\", \"c\": \"La réfraction\", \"d\"","_debug_options_count":4},{"id":25568,"question":"La lumière est une onde mécanique.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"La lumière est une onde électromagnétique, pas mécanique, car elle peut se propager dans le vide.","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":25569,"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 de 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":25570,"question":"Un diapason émet un son de fréquence 440 Hz. Quelle est sa période ?","option_a":"0,00227 s","option_b":"440 s","option_c":"227 s","option_d":"0,227 s","option_e":"","option_f":"","bonne_reponse":"a","explication":"La période T est l'inverse de la fréquence : T = 1\/f = 1\/440 ≈ 0,00227 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\": \"0,00227 s\", \"b\": \"440 s\", \"c\": \"227 s\", \"d\": \"0,227 s\"}}","_debug_options_count":4},{"id":25571,"question":"La diffraction est plus marquée lorsque la taille de l'obstacle est comparable à la longueur d'onde.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"C'est une propriété fondamentale de la diffraction : elle est maximale quand la taille de l'obstacle est de l'ordre de grandeur de 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\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":25572,"question":"Quelle est la vitesse de la lumière dans le vide (en m\/s) ?","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 vitesse de la lumière dans le vide est une constante fondamentale égale à 3 × 10⁸ m\/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":25573,"question":"Quel type d'onde est utilisé dans une échographie médicale ?","option_a":"Ondes radio","option_b":"Ondes sonores","option_c":"Ondes lumineuses","option_d":"Ondes X","option_e":"","option_f":"","bonne_reponse":"b","explication":"Les échographies utilisent des ondes ultrasonores (ondes sonores de haute fréquence) pour visualiser les organes internes.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Ondes radio\", \"b\": \"Ondes sonores\", \"c\": \"Ondes lumineuses\", \"d\":","_debug_options_count":4}]