Quiz — Serie 18- Ondes.pdf

Question 1 sur 10 20:00

[{"id":41340,"question":"Quelle grandeur physique reste constante lors du passage d'une onde d'un milieu à un autre ?","option_a":"La fréquence","option_b":"La célérité","option_c":"La longueur d'onde","option_d":"L'amplitude","option_e":"","option_f":"","bonne_reponse":"a","explication":"La fréquence d'une onde ne dépend pas du milieu de propagation. Elle reste constante lors du passage d'un milieu à un autre.","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\": \"La célérité\", \"c\": \"La longueur d'onde\",","_debug_options_count":4},{"id":41341,"question":"Une onde sonore se propage plus rapidement dans l'eau que dans l'air.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La célérité du son est plus élevée dans les milieux plus 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\": \"a\", \"options\": {\"a\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4},{"id":41342,"question":"Quelle relation lie la longueur d'onde λ, la célérité v et la période T d'une onde ?","option_a":"λ = v × T","option_b":"v = λ × T","option_c":"T = v × λ","option_d":"λ = v \/ T","option_e":"","option_f":"","bonne_reponse":"a","explication":"La bonne relation est λ = v × T, où T est la période (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\": \"λ = v × T\", \"b\": \"v = λ × T\", \"c\": \"T = v × λ\", \"d\": \"λ = ","_debug_options_count":4},{"id":41343,"question":"Quel phénomène se produit lorsque deux ondes de même fréquence et amplitude se superposent en phase ?","option_a":"Interférences destructives","option_b":"Interférences constructives","option_c":"Diffraction","option_d":"Réflexion","option_e":"","option_f":"","bonne_reponse":"b","explication":"Lorsque deux ondes en phase se superposent, elles donnent lieu à des interférences constructives, avec une amplitude résultante maximale.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"Interférences destructives\", \"b\": \"Interférences constructives\"","_debug_options_count":4},{"id":41344,"question":"La lumière visible fait partie du spectre des ondes électromagnétiques.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La lumière visible est une gamme de longueurs d'onde comprises entre 400 nm et 700 nm dans le spectre électromagnétique.","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":41345,"question":"Quelle est la fréquence d'une onde dont la longueur d'onde est de 500 nm et la célérité de 3×10⁸ m\/s ?","option_a":"6×10¹⁴ Hz","option_b":"1,5×10¹⁵ Hz","option_c":"6×10¹¹ Hz","option_d":"1,5×10¹² Hz","option_e":"","option_f":"","bonne_reponse":"a","explication":"La fréquence f = v \/ λ = (3×10⁸) \/ (500×10⁻⁹) = 6×10¹⁴ Hz.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"6×10¹⁴ Hz\", \"b\": \"1,5×10¹⁵ Hz\", \"c\": \"6×10¹¹ Hz\", \"d\":","_debug_options_count":4},{"id":41346,"question":"Quel type d'onde est utilisé dans les communications par fibre optique ?","option_a":"Ondes sonores","option_b":"Ondes radio","option_c":"Ondes lumineuses","option_d":"Ondes sismiques","option_e":"","option_f":"","bonne_reponse":"c","explication":"Les fibres optiques transmettent des signaux sous forme d'ondes lumineuses (laser) pour une communication rapide et à haut débit.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"Ondes sonores\", \"b\": \"Ondes radio\", \"c\": \"Ondes lumineuses\", \"d\":","_debug_options_count":4},{"id":41347,"question":"La diffraction est plus marquée lorsque la taille de l'obstacle est très grande devant 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 d'autant plus marquée que la taille de l'obstacle ou de l'ouverture est comparable à la longueur d'onde de l'onde incidente.","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":41348,"question":"Quelle est la célérité du son dans l'air à 20°C ?","option_a":"343 m\/s","option_b":"1500 m\/s","option_c":"5000 m\/s","option_d":"100 m\/s","option_e":"","option_f":"","bonne_reponse":"a","explication":"La célérité du son dans l'air à 20°C est d'environ 343 m\/s. Elle dépend de la température et de la composition du milieu.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"343 m\/s\", \"b\": \"1500 m\/s\", \"c\": \"5000 m\/s\", \"d\": \"100 m\/s\"}}","_debug_options_count":4},{"id":41349,"question":"Quel phénomène explique la formation des arcs-en-ciel ?","option_a":"La réflexion totale","option_b":"La diffraction","option_c":"La dispersion","option_d":"L'absorption","option_e":"","option_f":"","bonne_reponse":"c","explication":"La dispersion de la lumière blanche par les gouttes d'eau (réfraction différentielle selon les longueurs d'onde) explique la formation des arcs-en-ciel.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"La réflexion totale\", \"b\": \"La diffraction\", \"c\": \"La dispersion","_debug_options_count":4}]