Quiz — Devoir Contrôle N°1 Avec Correction - Bac Sciences - BAC.Org.tn.pdf

Question 1 sur 10 20:00

[{"id":27670,"question":"Quel est le pH d’une solution aqueuse de chlorure d’hydrogène (HCl) à 0,01 mol\/L ?","option_a":"A. 1","option_b":"B. 2","option_c":"C. 7","option_d":"D. 12","option_e":"","option_f":"","bonne_reponse":"b","explication":"Le pH d’une solution d’acide fort se calcule par pH = -log[H3O+]. Ici, [H3O+] = 0,01 mol\/L, donc pH = -log(0,01) = 2.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"A. 1\", \"b\": \"B. 2\", \"c\": \"C. 7\", \"d\": \"D. 12\"}}","_debug_options_count":4},{"id":27671,"question":"Dans un mouvement circulaire uniforme, l’accélération est toujours dirigée vers le centre de la trajectoire.","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 et responsable du changement de direction de la vitesse, sans modifier sa valeur.","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":27672,"question":"Quelle est la tension aux bornes d’un conducteur ohmique de résistance 50 Ω parcouru par un courant de 0,2 A ?","option_a":"A. 10 V","option_b":"B. 25 V","option_c":"C. 50 V","option_d":"D. 100 V","option_e":"","option_f":"","bonne_reponse":"a","explication":"La tension se calcule par U = R × I. Ici, U = 50 × 0,2 = 10 V.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"a\", \"options\": {\"a\": \"A. 10 V\", \"b\": \"B. 25 V\", \"c\": \"C. 50 V\", \"d\": \"D. 100 V\"}}","_debug_options_count":4},{"id":27673,"question":"Une onde sonore est une onde transversale.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"b","explication":"Faux. Les ondes sonores sont des ondes longitudinales : la perturbation se fait dans la même direction que la propagation de l’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":27674,"question":"Quel est le grandissement d’une lentille convergente si l’objet est placé à 20 cm de la lentille et l’image se forme à 60 cm de la lentille ?","option_a":"A. 0,33","option_b":"B. 3","option_c":"C. -3","option_d":"D. 0,5","option_e":"","option_f":"","bonne_reponse":"c","explication":"Le grandissement γ = -di\/do. Ici, γ = -60\/20 = -3. Le signe négatif indique que l’image est inversée.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"c\", \"options\": {\"a\": \"A. 0,33\", \"b\": \"B. 3\", \"c\": \"C. -3\", \"d\": \"D. 0,5\"}}","_debug_options_count":4},{"id":27675,"question":"La loi des mailles s’applique à un circuit électrique en série.","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 somme algébrique des tensions dans une maille fermée est nulle, applicable dans tout circuit.","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":27676,"question":"Un mobile de masse 2 kg a une énergie cinétique de 100 J. Quelle est sa vitesse ?","option_a":"A. 5 m\/s","option_b":"B. 10 m\/s","option_c":"C. 20 m\/s","option_d":"D. 50 m\/s","option_e":"","option_f":"","bonne_reponse":"b","explication":"L’énergie cinétique Ec = ½mv². Donc v = √(2Ec\/m) = √(2×100\/2) = √100 = 10 m\/s.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"b\", \"options\": {\"a\": \"A. 5 m\/s\", \"b\": \"B. 10 m\/s\", \"c\": \"C. 20 m\/s\", \"d\": \"D. 50 m\/s\"}}","_debug_options_count":4},{"id":27677,"question":"Le spectre d’une lumière blanche est continu.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La lumière blanche est composée de toutes les longueurs d’onde du visible, formant un spectre continu.","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":27678,"question":"Quelle est la période d’un pendule simple de longueur 1 m (g = 9,81 m\/s²) ?","option_a":"A. 0,5 s","option_b":"B. 1 s","option_c":"C. 2 s","option_d":"D. 4 s","option_e":"","option_f":"","bonne_reponse":"d","explication":"La période T = 2π√(L\/g). Ici, T = 2π√(1\/9,81) ≈ 2 s.","points":1,"type":"qcm","actif":1,"section_id":null,"ordre":0,"_debug_answer_data_type":"string","_debug_answer_data_preview":"{\"correct\": \"d\", \"options\": {\"a\": \"A. 0,5 s\", \"b\": \"B. 1 s\", \"c\": \"C. 2 s\", \"d\": \"D. 4 s\"}}","_debug_options_count":4},{"id":27679,"question":"La résistance équivalente de deux résistances en parallèle de 100 Ω et 200 Ω est de 66,67 Ω.","option_a":"Vrai","option_b":"Faux","option_c":"","option_d":"","option_e":"","option_f":"","bonne_reponse":"a","explication":"Vrai. La formule est Req = (R1×R2)\/(R1+R2) = (100×200)\/300 ≈ 66,67 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\": \"Vrai\", \"b\": \"Faux\", \"c\": \"\", \"d\": \"\"}}","_debug_options_count":4}]