Quiz — Devoir_synthese2.pdf

Question 1 sur 10 20:00

[{"id":20479,"question":"Quelle est la relation entre la force, la masse et l'accélération selon la 2ème loi de Newton ?","option_a":"F = m × a","option_b":"F = m \/ a","option_c":"F = a \/ m","option_d":"F = m + a","option_e":"","option_f":"","bonne_reponse":"a","explication":"La 2ème loi de Newton s'exprime par F = m × a, où F est la force nette, m la masse et a l'accélération.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"F = m × a\", \"b\": \"F = m \/ a\", \"c\": \"F = a \/ m\", \"d\": \"F = m + a\"","_debug_options_count":4},{"id":20480,"question":"Dans un circuit électrique en série, la tension totale est égale à la somme des tensions aux bornes de chaque dipôle.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La loi des mailles stipule que la tension totale est la somme des tensions aux bornes des dipôles en série.","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":20481,"question":"Quel est le pH d'une solution dont la concentration en ions H+ est de 10^-3 mol\/L ?","option_a":"pH = 3","option_b":"pH = 10","option_c":"pH = 11","option_d":"pH = 14","option_e":"","option_f":"","bonne_reponse":"a","explication":"Le pH est donné par pH = -log[H+]. Avec [H+] = 10^-3, pH = 3.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"pH = 3\", \"b\": \"pH = 10\", \"c\": \"pH = 11\", \"d\": \"pH = 14\"}}","_debug_options_count":4},{"id":20482,"question":"La puissance électrique P dissipée par un conducteur ohmique est donnée par la formule :","option_a":"P = U × I","option_b":"P = R × I²","option_c":"P = U² \/ R","option_d":"Toutes les réponses sont correctes","option_e":"","option_f":"","bonne_reponse":"d","explication":"Les trois formules sont équivalentes : P = U × I, P = R × I² et P = U² \/ R, grâce à la loi d'Ohm U = R × I.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"d\", \"options\": {\"a\": \"P = U × I\", \"b\": \"P = R × I²\", \"c\": \"P = U² \/ R\", \"d\": \"Toute","_debug_options_count":4},{"id":20483,"question":"Un corps en mouvement circulaire uniforme a une accélération centripète.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. L'accélération centripète est dirigée vers le centre de la trajectoire et maintient le mouvement circulaire.","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":20484,"question":"Quelle est la concentration molaire d'une solution de 2 moles de NaCl dissous dans 500 mL d'eau ?","option_a":"0,25 mol\/L","option_b":"4 mol\/L","option_c":"2 mol\/L","option_d":"1 mol\/L","option_e":"","option_f":"","bonne_reponse":"c","explication":"La concentration molaire C = n\/V = 2 mol \/ 0,5 L = 4 mol\/L.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"0,25 mol\/L\", \"b\": \"4 mol\/L\", \"c\": \"2 mol\/L\", \"d\": \"1 mol\/L\"}}","_debug_options_count":4},{"id":20485,"question":"Dans un circuit en parallèle, l'intensité totale est égale à la somme des intensités dans chaque branche.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La loi des nœuds stipule que l'intensité totale est la somme des intensités dans chaque branche en parallèle.","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":20486,"question":"Quelle est l'énergie cinétique d'un corps de masse 2 kg se déplaçant à 3 m\/s ?","option_a":"9 J","option_b":"18 J","option_c":"6 J","option_d":"3 J","option_e":"","option_f":"","bonne_reponse":"a","explication":"L'énergie cinétique Ec = ½ × m × v² = ½ × 2 × 3² = 9 J.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"9 J\", \"b\": \"18 J\", \"c\": \"6 J\", \"d\": \"3 J\"}}","_debug_options_count":4},{"id":20487,"question":"Le titrage d'un acide par une base permet de déterminer le pH de la solution finale.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Faux. Le titrage permet de déterminer la concentration de l'acide ou de la base, mais pas directement le pH final.","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":20488,"question":"Quelle est la résistance équivalente de deux résistances de 4 Ω et 6 Ω montées en série ?","option_a":"10 Ω","option_b":"24 Ω","option_c":"2,4 Ω","option_d":"1,5 Ω","option_e":"","option_f":"","bonne_reponse":"a","explication":"En série, la résistance équivalente Req = R1 + R2 = 4 Ω + 6 Ω = 10 Ω.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"10 Ω\", \"b\": \"24 Ω\", \"c\": \"2,4 Ω\", \"d\": \"1,5 Ω\"}}","_debug_options_count":4}]