{"save":1,"level":1,"time":"50","total":40,"point":5,"segment":[{"id":"7753","test_id":"604","question":"<p>Trong qu&aacute; tr&igrave;nh \u0111\u1eb3ng &aacute;p c\u1ee7a m\u1ed9t kh\u1ed1i l&iacute; t\u01b0\u1edfng x&aacute;c \u0111\u1ecbnh,&nbsp;<\/p>","options":["<strong>A.<\/strong>&nbsp;nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u1ed1i kh&iacute; kh&ocirc;ng \u0111\u1ed5i.","<strong>B.<\/strong>&nbsp;th\u1ec3 t&iacute;ch c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m khi nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m.","<strong>C.<\/strong>&nbsp;th\u1ec3 t&iacute;ch c\u1ee7a kh\u1ed1i kh&iacute; kh&ocirc;ng \u0111\u1ed5i.","<strong>D.<\/strong>&nbsp;th\u1ec3 t&iacute;ch c\u1ee7a kh\u1ed1i kh&iacute; t\u0103ng khi nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m."],"correct":"2","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong>&nbsp;th\u1ec3 t&iacute;ch c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m khi nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m.<\/span><\/p><p>Trong qu&aacute; tr&igrave;nh \u0111\u1eb3ng &aacute;p c\u1ee7a m\u1ed9t kh\u1ed1i l&iacute; t\u01b0\u1edfng x&aacute;c \u0111\u1ecbnh,&nbsp;th\u1ec3 t&iacute;ch c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m khi nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u1ed1i kh&iacute; gi\u1ea3m.<\/p>","type":"choose","user_id":"131","test":"0","date":"2025-07-06 07:55:35"},{"id":"7755","test_id":"604","question":"<p>M\u1ed9t \u0111o\u1ea1n d&acirc;y d\u1eabn th\u1eb3ng c&oacute; chi\u1ec1u d&agrave;i&nbsp;<span class=\"math-tex\">$\\ell$<\/span>&nbsp;mang d&ograve;ng \u0111i\u1ec7n c&oacute; c\u01b0\u1eddng \u0111\u1ed9&nbsp;<span class=\"math-tex\">$I$<\/span>&nbsp;\u0111\u01b0\u1ee3c \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng \u0111\u1ec1u v\u1edbi g&oacute;c h\u1ee3p b\u1edfi chi\u1ec1u d&ograve;ng \u0111i\u1ec7n v&agrave; chi\u1ec1u c\u1ea3m \u1ee9ng t\u1eeb c\u1ee7a t\u1eeb tr\u01b0\u1eddng l&agrave;&nbsp;<span class=\"math-tex\">$\\alpha$<\/span>. L\u1ef1c t\u1eeb do t\u1eeb tr\u01b0\u1eddng n&agrave;y t&aacute;c d\u1ee5ng l&ecirc;n \u0111o\u1ea1n d&acirc;y c&oacute; \u0111\u1ed9 l\u1edbn l&agrave;&nbsp;<span class=\"math-tex\">$F$<\/span>. \u0110\u1ed9 l\u1edbn c\u1ea3m \u1ee9ng t\u1eeb&nbsp;<span class=\"math-tex\">$B$<\/span>&nbsp;c\u1ee7a t\u1eeb tr\u01b0\u1eddng l&agrave;<\/p>","options":["<strong>A.<\/strong>&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\tan\\alpha}$<\/span>","<strong>B.<\/strong>&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\sin\\alpha}$<\/span>","<strong>C.<\/strong>&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\cot\\alpha}$<\/span>","<strong>D.<\/strong>&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\cos\\alpha}$<\/span>"],"correct":"2","answer":"<p>Ch\u1ecdn&nbsp;<span style=\"color:#16a085;\"><strong>B.<\/strong>&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\sin\\alpha}$<\/span>.<\/span><\/p><p><span class=\"math-tex\">$F=BI\\ell\\sin\\alpha$<\/span>&nbsp;&rArr;&nbsp;<span class=\"math-tex\">$B=\\dfrac{F}{I\\ell\\sin\\alpha}$<\/span>.<\/p>","type":"choose","user_id":"131","test":"1","date":"2025-07-06 07:55:47"}]}