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{"common":{"save":0,"post_id":"8113","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8944","post_id":"8113","mon_id":"1159533","chapter_id":"1159595","question":"M\u1ed9t tia sáng truy\u1ec1n t\u1eeb không khí vào n\u01b0\u1edbc v\u1edbi góc t\u1edbi 45°, chi\u1ebft su\u1ea5t c\u1ee7a n\u01b0\u1edbc là 1,33. Góc khúc x\u1ea1 g\u1ea7n nh\u1ea5t v\u1edbi giá tr\u1ecb nào sau \u0111ây?<\/p>","options":["A. 30°","B. 32°","C. 28°","D. 40°"],"correct":"2","level":"2","hint":"Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt khúc x\u1ea1 ánh sáng: $n = {\\sin i \\over \\sin r}$<\/span><\/p>","answer":"\u0110áp án<\/strong>: B Gi\u1ea3i thích<\/strong>: Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt khúc x\u1ea1 ánh sáng: $n = {\\sin i \\over \\sin r}$<\/span> => $\\sin r = {\\sin i \\over n}$<\/span><\/p>Thay $i = 45$<\/span>° và $n = 1,33$<\/span>, ta có:<\/p>$\\sin r = {\\sin 45\u00b0 \\over 1,33}$<\/span> ≈ $ {0,707 \\over 1,33}$<\/span> ≈ 0,531<\/p>=> r ≈ 32°<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-11-30 20:25:03","option_type":"txt","len":0},{"id":"8945","post_id":"8113","mon_id":"1159533","chapter_id":"1159595","question":"Tia sáng truy\u1ec1n t\u1eeb n\u01b0\u1edbc vào không khí (chi\u1ebft su\u1ea5t c\u1ee7a n\u01b0\u1edbc là 1,33). N\u1ebfu góc khúc x\u1ea1 là 30°, góc t\u1edbi g\u1ea7n \u0111úng là bao nhiêu?<\/p>","options":["A. 30°","B. 40°","C. 42°","D. 50°"],"correct":"3","level":"2","hint":"Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt khúc x\u1ea1: $n = {\\sin i \\over \\sin r}$<\/span><\/p>","answer":"\u0110áp án: C<\/p>Gi\u1ea3i thích: <\/p>Áp d\u1ee5ng \u0111\u1ecbnh lu\u1eadt khúc x\u1ea1: $n = {\\sin i \\over \\sin r}$<\/span> => $\\sin i = n.\\sin r$<\/span><\/p>Thay r = 30° và n = 1,33<\/p>$\\sin i = 1,33.\\sin 30 \u00b0 = 0,665$<\/span><\/p>=> i = 41,68 ≈ 42°<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-11-30 20:35:18","option_type":"txt","len":0},{"id":"8946","post_id":"8113","mon_id":"1159533","chapter_id":"1159595","question":"Tia sáng truy\u1ec1n t\u1eeb không khí vào n\u01b0\u1edbc v\u1edbi chi\u1ebft su\u1ea5t 1,33. Tìm góc gi\u1edbi h\u1ea1n ph\u1ea3n x\u1ea1 toàn ph\u1ea7n t\u1ea1i m\u1eb7t phân cách n\u01b0\u1edbc và không khí.<\/p>","options":["$A. 41,8^\\circ$<\/span>","$\n$<\/span>B. 48,6°","C. 49,5°","D. 50,2°"],"correct":"1","level":"2","hint":"S\u1eed d\u1ee5ng công th\u1ee9c ph\u1ea3n x\u1ea1 toàn ph\u1ea7n: $\\sin i_g = {n_2 \\over n_1}$<\/span><\/p>","answer":"\u0110áp án<\/strong>: A Gi\u1ea3i thích<\/strong>: Góc gi\u1edbi h\u1ea1n ph\u1ea3n x\u1ea1 toàn ph\u1ea7n \u0111\u01b0\u1ee3c xác \u0111\u1ecbnh b\u1edfi công th\u1ee9c: $\\sin i_g = {n_2 \\over n_1}$<\/span><\/p>v\u1edbi $n_1$<\/span> là chi\u1ebft su\u1ea5t c\u1ee7a n\u01b0\u1edbc(1,33) và $n_2$<\/span> là chi\u1ebft su\u1ea5t c\u1ee7a không khí (x\u1ea5p x\u1ec9 1):<\/p>$\\sin i_g = {1\\over 1,33} $<\/span> ≈ 0,751<\/p>=> $i_g$<\/span> ≈ $41,8^\\circ$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-01 08:28:04","option_type":"math","len":0}]}