{"segment":[{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"V\u00ec sao l\u00f5i c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n kh\u00f4ng l\u00e0m b\u1eb1ng th\u00e9p m\u00e0 l\u1ea1i l\u00e0m b\u1eb1ng s\u1eaft non?","select":["A. V\u00ec l\u00f5i th\u00e9p nhi\u1ec5m t\u1eeb y\u1ebfu h\u01a1n l\u00f5i s\u1eaft non.","B. V\u00ec d\u00f9ng l\u00f5i th\u00e9p th\u00ec sau khi b\u1ecb nhi\u1ec5m t\u1eeb s\u1ebd bi\u1ebfn th\u00e0nh m\u1ed9t nam ch\u00e2m v\u0129nh c\u1eedu.","C. V\u00ec d\u00f9ng l\u00f5i th\u00e9p th\u00ec kh\u00f4ng th\u1ec3 l\u00e0m thay \u0111\u1ed5i c\u01b0\u1eddng \u0111\u1ed9 l\u1ef1c \u0111i\u1ec7n t\u1eeb c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n.","D. V\u00ec d\u00f9ng l\u00f5i th\u00e9p th\u00ec l\u1ef1c t\u1eeb b\u1ecb gi\u1ea3m \u0111i so v\u1edbi khi ch\u01b0a c\u00f3 l\u00f5i."],"hint":"","explain":"<span class='basic_left'>L\u00f5i c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n kh\u00f4ng l\u00e0m b\u1eb1ng th\u00e9p m\u00e0 l\u1ea1i l\u00e0m b\u1eb1ng s\u1eaft non v\u00ec: <br\/>V\u00ec d\u00f9ng l\u00f5i th\u00e9p th\u00ec sau khi b\u1ecb nhi\u1ec5m t\u1eeb s\u1ebd bi\u1ebfn th\u00e0nh m\u1ed9t nam ch\u00e2m v\u0129nh c\u1eedu.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3131},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"C\u00f3 hi\u1ec7n t\u01b0\u1ee3ng g\u00ec x\u1ea3y ra v\u1edbi m\u1ed9t thanh th\u00e9p khi \u0111\u1eb7t n\u00f3 v\u00e0o trong l\u00f2ng m\u1ed9t \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n m\u1ed9t chi\u1ec1u ch\u1ea1y qua?","select":["A. Thanh th\u00e9p b\u1ecb n\u00f3ng l\u00ean.","B. Thanh th\u00e9p b\u1ecb ph\u00e1t s\u00e1ng.","C. Thanh th\u00e9p b\u1ecb \u0111\u1ea9y ra kh\u1ecfi \u1ed1ng d\u00e2y.","D. Thanh th\u00e9p tr\u1edf th\u00e0nh m\u1ed9t nam ch\u00e2m."],"hint":"","explain":"<span class='basic_left'>Khi \u0111\u1eb7t m\u1ed9t thanh th\u00e9p v\u00e0o trong l\u00f2ng m\u1ed9t \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n m\u1ed9t chi\u1ec1u ch\u1ea1y qua th\u00ec thanh th\u00e9p tr\u1edf th\u00e0nh m\u1ed9t nam ch\u00e2m.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":3132},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Trong c\u00e1c tr\u01b0\u1eddng h\u1ee3p sau, tr\u01b0\u1eddng h\u1ee3p n\u00e0o v\u1eadt c\u00f3 kh\u1ea3 n\u0103ng nhi\u1ec5m t\u1eeb v\u00e0 tr\u1edf th\u00e0nh nam ch\u00e2m v\u0129nh c\u1eedu?","select":["A. M\u1ed9t v\u00f2ng d\u00e2y d\u1eabn b\u1eb1ng th\u00e9p \u0111\u01b0\u1ee3c \u0111\u01b0a l\u1ea1i g\u1ea7n m\u1ed9t c\u1ef1c c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n m\u1ea1nh trong th\u1eddi gian ng\u1eafn, r\u1ed3i \u0111\u01b0a ra xa.","B. M\u1ed9t v\u00f2ng d\u00e2y d\u1eabn b\u1eb1ng s\u1eaft non \u0111\u01b0\u1ee3c \u0111\u01b0a l\u1ea1i g\u1ea7n m\u1ed9t c\u1ef1c c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n m\u1ea1nh trong th\u1eddi gian ng\u1eafn, r\u1ed3i \u0111\u01b0a ra xa.","C. M\u1ed9t v\u00f2ng d\u00e2y d\u1eabn b\u1eb1ng s\u1eaft non \u0111\u01b0\u1ee3c \u0111\u01b0a l\u1ea1i g\u1ea7n m\u1ed9t \u0111\u1ea7u c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n m\u1ea1nh trong th\u1eddi gian d\u00e0i, r\u1ed3i \u0111\u01b0a ra xa.","D. M\u1ed9t l\u00f5i s\u1eaft non \u0111\u01b0\u1ee3c \u0111\u1eb7t trong l\u00f2ng m\u1ed9t cu\u1ed9n d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn trong m\u1ed9t th\u1eddi gian d\u00e0i, r\u1ed3i \u0111\u01b0a ra xa."],"hint":"","explain":"<span class='basic_left'> Tr\u01b0\u1eddng h\u1ee3p v\u1eadt c\u00f3 kh\u1ea3 n\u0103ng nhi\u1ec5m t\u1eeb v\u00e0 tr\u1edf th\u00e0nh nam ch\u00e2m v\u0129nh c\u1eedu:<br\/> M\u1ed9t v\u00f2ng d\u00e2y d\u1eabn b\u1eb1ng th\u00e9p \u0111\u01b0\u1ee3c \u0111\u01b0a l\u1ea1i g\u1ea7n m\u1ed9t c\u1ef1c c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n m\u1ea1nh trong th\u1eddi gian ng\u1eafn, r\u1ed3i \u0111\u01b0a ra xa.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":3133},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Khi \u0111\u1eb7t m\u1ed9t thanh s\u1eaft non v\u00e0o trong l\u00f2ng m\u1ed9t \u1ed1ng d\u00e2y d\u1eabn c\u00f3 d\u00f2ng \u0111i\u1ec7n m\u1ed9t chi\u1ec1u ch\u1ea1y qua th\u00ec thanh s\u1eaft tr\u1edf th\u00e0nh m\u1ed9t nam ch\u00e2m. H\u01b0\u1edbng B\u1eafc Nam c\u1ee7a m\u1ed9t nam ch\u00e2m m\u1edbi \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh so v\u1edbi h\u01b0\u1edbng B\u1eafc Nam c\u1ee7a \u1ed1ng \u0111\u00e2y th\u00ec?","select":["A. C\u00f9ng h\u01b0\u1edbng.","B. Ng\u01b0\u1ee3c h\u01b0\u1edbng.","C. Vu\u00f4ng g\u00f3c.","D. T\u1ea1o th\u00e0nh m\u1ed9t g\u00f3c $45{}^\\circ $."],"hint":"","explain":"<span class='basic_left'>Do s\u1eaft non b\u1ecb nhi\u1ec5m t\u1eeb c\u1ee7a \u1ed1ng d\u00e2y n\u00ean tr\u00ean th\u00e0nh nam ch\u00e2m, khi ng\u1eaft \u0111i\u1ec7n th\u00ec s\u1eaft non m\u1ea5t h\u1ebft t\u1eeb t\u00ednh. Do \u0111\u00f3 n\u1ebfu \u0111\u1ea7u n\u00e0o c\u1ee7a \u1ed1ng d\u00e2y l\u00e0 c\u1ef1c g\u00ec th\u00ec thanh s\u1eaft non s\u1ebd c\u00f3 c\u1ef1c t\u00ednh \u0111\u00f3.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":3134},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"Kim lo\u1ea1i gi\u1eef \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh l\u00e2u d\u00e0i sau khi \u0111\u00e3 b\u1ecb nhi\u1ec5m t\u1eeb l\u00e0?","select":["A. \u0110\u1ed3ng.","B. S\u1eaft non.","C. Th\u00e9p.","D. S\u1eaft."],"hint":"","explain":"<span class='basic_left'>Kim lo\u1ea1i gi\u1eef \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh l\u00e2u d\u00e0i sau khi \u0111\u00e3 b\u1ecb nhi\u1ec5m t\u1eeb l\u00e0 th\u00e9p. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3135},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Nh\u1eefng v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 b\u1ecb nhi\u1ec5m t\u1eeb khi \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng l\u00e0?","select":["A. \u0110\u1ed3ng, nh\u00f4m, s\u1eaft, th\u00e9p.","B. Niken, th\u00e9p, coban, s\u1eaft.","C. Th\u00e9p, coban, nh\u00f4m, s\u1eaft.","D. S\u1eaft, \u0111\u1ed3ng, th\u00e9p, niken."],"hint":"","explain":"<span class='basic_left'>Nh\u1eefng v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 b\u1ecb nhi\u1ec5m t\u1eeb khi \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng l\u00e0 Niken, th\u00e9p, coban, s\u1eaft.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3136},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"C\u00f3 c\u00e1ch n\u00e0o \u0111\u1ec3 l\u00e0m t\u0103ng l\u1ef1c t\u1eeb c\u1ee7a m\u1ed9t nam ch\u00e2m \u0111i\u1ec7n?","select":["A. D\u00f9ng d\u00e2y d\u1eabn to qu\u1ea5n \u00edt v\u00f2ng.","B. D\u00f9ng d\u00e2y d\u1eabn nh\u1ecf qu\u1ea5n nhi\u1ec1u v\u00f2ng.","C. T\u0103ng s\u1ed1 v\u00f2ng d\u00e2y d\u1eabn v\u00e0 gi\u1ea3m hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u \u1ed1ng d\u00e2y.","D. T\u0103ng \u0111\u01b0\u1eddng k\u00ednh v\u00e0 chi\u1ec1u d\u00e0i \u1ed1ng d\u00e2y."],"hint":"","explain":"<span class='basic_left'>C\u00f3 nh\u1eefng c\u00e1ch sau \u0111\u1ec3 t\u0103ng l\u1ef1c t\u1eeb c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n:<br\/>Gi\u1eef nguy\u00ean s\u1ed1 v\u00f2ng d\u00e2y qu\u1ea5n v\u00e0 t\u0103ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n<br\/>Gi\u1eef nguy\u00ean c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0 t\u0103ng s\u1ed1 v\u00f2ng d\u00e2y qu\u1ea5n<br\/>T\u0103ng c\u1ea3 c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0 s\u1ed1 v\u00f2ng d\u00e2y qu\u1ea5n.<br\/>Cho n\u00ean c\u00e2u B l\u00e0 \u0111\u00fang v\u00ec t\u0103ng s\u1ed1 v\u00f2ng d\u00e2y qu\u1ea5n gi\u1eef nguy\u00ean hi\u1ec7u \u0111i\u1ec7n th\u1ebf c\u00f3 ngh\u0129a l\u00e0 gi\u1eef nguy\u00ean c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n n\u00ean k\u1ebft qu\u1ea3 l\u00e0 t\u0103ng \u0111\u01b0\u1ee3c l\u1ef1c t\u1eeb c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3137},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/vatly/bai25/lv2/img\/h6.jpg'\/><\/center>Nam ch\u00e2m \u0111i\u1ec7n \u1edf h\u00ecnh n\u00e0o sau \u0111\u00e2y c\u00f3 l\u1ef1c t\u1eeb m\u1ea1nh nh\u1ea5t ?","select":["A. H\u00ecnh b. ","B. C\u1ea3 ba \u0111\u1ec1u m\u1ea1nh nh\u01b0 nhau.","C. H\u00ecnh c.","D. H\u00ecnh a."],"hint":"","explain":"<span class='basic_left'>S\u1ed1 v\u00f2ng c\u00e0ng nhi\u1ec1u th\u00ec nam ch\u00e2m \u0111i\u1ec7n c\u00e0ng m\u1ea1nh.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3138},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"\u0110i\u1ec1u n\u00e0o sau \u0111\u00e2y l\u00e0 \u0111\u00fang khi n\u00f3i v\u1ec1 s\u1ef1 nhi\u1ec5m t\u1eeb c\u1ee7a s\u1eaft ?","select":["A. S\u1ef1 nhi\u1ec5m t\u1eeb c\u1ee7a s\u1eaft \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng trong vi\u1ec7c ch\u1ebf t\u1ea1o nam ch\u00e2m \u0111i\u1ec7n.","B. S\u1eaft \u0111\u1eb7t trong \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, n\u00f3 s\u1ebd b\u1ecb nhi\u1ec5m t\u1eeb.","C. Khi l\u00f5i s\u1eaft trong \u1ed1ng d\u00e2y \u0111ang b\u1ecb nhi\u1ec5m t\u1eeb, n\u1ebfu c\u1eaft d\u00f2ng \u0111i\u1ec7n th\u00ec l\u00f5i s\u1eaft s\u1ebd m\u1ea5t t\u1eeb t\u00ednh.","D. C\u1ea3 ba ph\u01b0\u01a1ng \u00e1n \u0111\u00fang."],"hint":"","explain":"<span class='basic_left'>S\u1ef1 nhi\u1ec5m t\u1eeb c\u1ee7a s\u1eaft \u0111\u01b0\u1ee3c \u1ee9ng d\u1ee5ng trong vi\u1ec7c ch\u1ebf t\u1ea1o nam ch\u00e2m \u0111i\u1ec7n. S\u1eaft \u0111\u1eb7t trong \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, n\u00f3 s\u1ebd b\u1ecb nhi\u1ec5m t\u1eeb. Khi l\u00f5i s\u1eaft trong \u1ed1ng d\u00e2y \u0111ang b\u1ecb nhi\u1ec5m t\u1eeb, n\u1ebfu c\u1eaft d\u00f2ng \u0111i\u1ec7n th\u00ec l\u00f5i s\u1eaft s\u1ebd m\u1ea5t t\u1eeb t\u00ednh. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":3139},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Nam ch\u00e2m \u0111i\u1ec7n c\u00f3 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m n\u00e0o l\u1ee3i th\u1ebf h\u01a1n nam ch\u00e2m v\u0129nh c\u1eedu ? ","select":["A. C\u00f3 th\u1ec3 ch\u1ebf t\u1ea1o nam ch\u00e2m \u0111i\u1ec7n r\u1ea5t m\u1ea1nh b\u1eb1ng c\u00e1ch t\u0103ng s\u1ed1 v\u00f2ng d\u00e2y v\u00e0 t\u0103ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u1ed1ng d\u00e2y.","B. C\u1ea3 ba ph\u01b0\u01a1ng \u00e1n \u0111\u00fang.","C. C\u00f3 th\u1ec3 thay \u0111\u1ed5i t\u00ean t\u1eeb c\u1ef1c c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n b\u1eb1ng c\u00e1ch \u0111\u1ed5i chi\u1ec1u d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u1ed1ng d\u00e2y.","D. Ch\u1ec9 c\u1ea7n ng\u1eaft \u0111i\u1ec7n \u0111i qua \u1ed1ng d\u00e2y l\u00e0 nam ch\u00e2m \u0111i\u1ec7n m\u1ea5t h\u1ebft t\u1eeb t\u00ednh."],"hint":"","explain":"<span class='basic_left'>Nam ch\u00e2m \u0111i\u1ec7n c\u00f3 nh\u1eefng \u0111\u1eb7c \u0111i\u1ec3m l\u1ee3i th\u1ebf h\u01a1n nam ch\u00e2m v\u0129nh c\u1eedu: <br\/>C\u00f3 th\u1ec3 ch\u1ebf t\u1ea1o nam ch\u00e2m \u0111i\u1ec7n r\u1ea5t m\u1ea1nh b\u1eb1ng c\u00e1ch t\u0103ng s\u1ed1 v\u00f2ng d\u00e2y v\u00e0 t\u0103ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u1ed1ng d\u00e2y. <br\/>C\u00f3 th\u1ec3 thay \u0111\u1ed5i t\u00ean t\u1eeb c\u1ef1c c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n b\u1eb1ng c\u00e1ch \u0111\u1ed5i chi\u1ec1u d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u1ed1ng d\u00e2y.<br\/>Ch\u1ec9 c\u1ea7n ng\u1eaft \u0111i\u1ec7n \u0111i qua \u1ed1ng d\u00e2y l\u00e0 nam ch\u00e2m \u0111i\u1ec7n m\u1ea5t h\u1ebft t\u1eeb t\u00ednh.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3140},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"C\u1ea5u t\u1ea1o c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n \u0111\u01a1n gi\u1ea3n g\u1ed3m :","select":["A. M\u1ed9t s\u1ee3i d\u00e2y d\u1eabn \u0111i\u1ec7n qu\u1ea5n th\u00e0nh nhi\u1ec1u v\u00f2ng \u1edf gi\u1eefa c\u00f3 l\u00f5i \u0111\u1ed3ng.","B. M\u1ed9t cu\u1ed9n d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, trong \u0111\u00f3 c\u00f3 m\u1ed9t l\u00f5i s\u1eaft.","C. M\u1ed9t cu\u1ed9n d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, trong \u0111\u00f3 c\u00f3 m\u1ed9t l\u00f5i nam ch\u00e2m.","D. C\u1ea3 3 \u0111\u00e1p \u00e1n \u0111\u00fang."],"hint":"","explain":"<span class='basic_left'>C\u1ea5u t\u1ea1o c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n \u0111\u01a1n gi\u1ea3n g\u1ed3m: M\u1ed9t cu\u1ed9n d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, trong \u0111\u00f3 c\u00f3 m\u1ed9t l\u00f5i s\u1eaft. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3141},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Khi ch\u1ea1m m\u0169i dao b\u1eb1ng th\u00e9p v\u00e0o \u0111\u1ea7u nam ch\u00e2m m\u1ed9t th\u1eddi gian th\u00ec sau \u0111\u00f3 m\u0169i giao h\u00fat \u0111\u01b0\u1ee3c c\u00e1c v\u1ee5n s\u1eaft. C\u00e2u gi\u1ea3i th\u00edch n\u00e0o sau \u0111\u00e2y \u0111\u00fang ?","select":["A. Do m\u0169i dao b\u1ecb nhi\u1ec5m t\u1eeb.","B. Do m\u0169i dao b\u1ecb ma s\u00e1t m\u1ea1nh.","C. Do m\u0169i dao kh\u00f4ng duy tr\u00ec \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh.","D. Do m\u0169i dao b\u1ecb n\u00f3ng l\u00ean."],"hint":"","explain":"<span class='basic_left'>Khi ch\u1ea1m m\u0169i dao b\u1eb1ng th\u00e9p v\u00e0o \u0111\u1ea7u nam ch\u00e2m m\u1ed9t th\u1eddi gian th\u00ec m\u0169i dao b\u1ecb nhi\u1ec5m t\u1eeb, n\u00ean sau \u0111\u00f3 m\u0169i giao h\u00fat \u0111\u01b0\u1ee3c c\u00e1c v\u1ee5n s\u1eaft.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":3142},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Tr\u00ean cu\u1ed9n d\u00e2y c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n c\u00f3 ghi 2,5A - 40\u03a9. \u00dd ngh\u0129a c\u1ee7a c\u00e1c con s\u1ed1 n\u00e0y l\u00e0 g\u00ec ? Ch\u1ecdn c\u00e2u tr\u1ea3 l\u1eddi \u0111\u00fang trong c\u00e1c c\u00e2u tr\u1ea3 l\u1eddi sau :","select":["A. Con s\u1ed1 2,5A cho bi\u1ebft c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n l\u1edbn nh\u1ea5t m\u00e0 \u1ed1ng d\u00e2y c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c. Con s\u1ed1 40\u03a9 cho bi\u1ebft \u0111i\u1ec7n tr\u1edf c\u1ee7a to\u00e0n b\u1ed9 \u1ed1ng d\u00e2y.","B. Con s\u1ed1 2,5A cho bi\u1ebft c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n nh\u1ecf nh\u1ea5t m\u00e0 \u1ed1ng d\u00e2y c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c. Con s\u1ed1 40\u03a9 cho bi\u1ebft \u0111i\u1ec7n tr\u1edf c\u1ee7a to\u00e0n b\u1ed9 \u1ed1ng d\u00e2y.","C. Con s\u1ed1 2,5A cho bi\u1ebft c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c c\u1ee7a \u1ed1ng d\u00e2y. Con s\u1ed1 40\u03a9 cho bi\u1ebft \u0111i\u1ec7n tr\u1edf \u0111\u1ecbnh m\u1ee9c c\u1ee7a \u1ed1ng d\u00e2y. ","D. Con s\u1ed1 2,5A cho bi\u1ebft c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n l\u1edbn nh\u1ea5t m\u00e0 \u1ed1ng d\u00e2y c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c. Con s\u1ed1 40\u03a9 cho bi\u1ebft \u0111i\u1ec7n tr\u1edf c\u1ee7a m\u1ed7i v\u00f2ng c\u1ee7a \u1ed1ng d\u00e2y."],"hint":"","explain":"<span class='basic_left'>Tr\u00ean cu\u1ed9n d\u00e2y c\u1ee7a nam ch\u00e2m \u0111i\u1ec7n c\u00f3 ghi 2,5A - 40\u03a9. Con s\u1ed1 2,5A cho bi\u1ebft c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n l\u1edbn nh\u1ea5t m\u00e0 \u1ed1ng d\u00e2y c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c. Con s\u1ed1 40\u03a9 cho bi\u1ebft \u0111i\u1ec7n tr\u1edf c\u1ee7a to\u00e0n b\u1ed9 \u1ed1ng d\u00e2y. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":3143},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Ng\u01b0\u1eddi ta c\u00f3 th\u1ec3 ch\u1ebf t\u1ea1o nam ch\u00e2m v\u0129nh c\u1eedu b\u1eb1ng c\u00e1ch \u0111\u1eb7t m\u1ed9t thanh kim lo\u1ea1i trong \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, thanh kim lo\u1ea1i b\u1ecb nhi\u1ec5m t\u1eeb. Thanh kim lo\u1ea1i \u0111\u01b0\u1ee3c d\u00f9ng l\u00e0 :","select":["A. Thanh \u0111\u1ed3ng.","B. Thanh th\u00e9p.","C. Thanh nh\u00f4m.","D. B\u1ea5t c\u1ee9 thanh kim lo\u1ea1i n\u00e0o."],"hint":"","explain":"<span class='basic_left'>Ng\u01b0\u1eddi ta c\u00f3 th\u1ec3 ch\u1ebf t\u1ea1o nam ch\u00e2m v\u0129nh c\u1eedu b\u1eb1ng c\u00e1ch \u0111\u1eb7t m\u1ed9t thanh th\u00e9p trong \u1ed1ng d\u00e2y c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua, thanh th\u00e9p b\u1ecb nhi\u1ec5m t\u1eeb k\u1ec3 c\u1ea3 khi b\u1ecf n\u00f3 ra kh\u1ecfi t\u1eeb tr\u01b0\u1eddng c\u1ee7a \u1ed1ng d\u00e2y, n\u00ean thanh th\u00e9p \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 ch\u1ebf t\u1ea1o nam ch\u00e2m v\u0129nh c\u1eedu.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3144},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"Trong c\u00e1c c\u00e1ch gi\u1ea3i th\u00edch v\u00ec sao m\u1ed9t v\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb sau \u0111\u00e2y, c\u00e1ch gi\u1ea3i th\u00edch n\u00e0o l\u00e0 h\u1ee3p l\u00ed nh\u1ea5t ?","select":["A. V\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb l\u00e0 do ch\u00fang b\u1ecb n\u00f3ng l\u00ean.","B. V\u1eadt n\u00e0o c\u0169ng c\u1ea5u t\u1ea1o t\u1eeb c\u00e1c ph\u1ea7n t\u1eed. Trong ph\u1ea7n t\u1eed n\u00e0o c\u0169ng c\u00f3 d\u00f2ng \u0111i\u1ec7n n\u00ean v\u1ec1 ph\u01b0\u01a1ng di\u1ec7n \u0111i\u1ec7n t\u1eeb, m\u1ed7i ph\u1ea7n t\u1eed c\u00f3 th\u1ec3 coi nh\u01b0 m\u1ed9t thanh nam ch\u00e2m r\u1ea5t b\u00e9. Khi v\u1eadt \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng nh\u1eefng 'thanh nam ch\u00e2m r\u1ea5t b\u00e9' n\u00e0y s\u1eafp x\u1ebfp c\u00f3 tr\u1eadt t\u1ef1 n\u00ean v\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb.","C. V\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb l\u00e0 do c\u00f3 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3.","D. V\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb l\u00e0 do xung quanh Tr\u00e1i \u0110\u1ea5t lu\u00f4n c\u00f3 t\u1eeb tr\u01b0\u1eddng."],"hint":"","explain":"<span class='basic_left'>V\u1eadt n\u00e0o c\u0169ng c\u1ea5u t\u1ea1o t\u1eeb c\u00e1c ph\u1ea7n t\u1eed. Trong ph\u1ea7n t\u1eed n\u00e0o c\u0169ng c\u00f3 d\u00f2ng \u0111i\u1ec7n n\u00ean v\u1ec1 ph\u01b0\u01a1ng di\u1ec7n \u0111i\u1ec7n t\u1eeb, m\u1ed7i ph\u1ea7n t\u1eed c\u00f3 th\u1ec3 coi nh\u01b0 m\u1ed9t thanh nam ch\u00e2m r\u1ea5t b\u00e9. Khi v\u1eadt \u0111\u1eb7t trong t\u1eeb tr\u01b0\u1eddng nh\u1eefng 'thanh nam ch\u00e2m r\u1ea5t b\u00e9' n\u00e0y s\u1eafp x\u1ebfp c\u00f3 tr\u1eadt t\u1ef1 n\u00ean v\u1eadt b\u1ecb nhi\u1ec5m t\u1eeb. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3145},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/vatly/bai25/lv2/img\/h14.jpg'\/><\/center>Hai nam ch\u00e2m \u0111i\u1ec7n \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o t\u1eeb c\u00f9ng m\u1ed9t lo\u1ea1i l\u00f5i s\u1eaft, c\u00e1c cu\u1ed9n d\u00e2y c\u00f3 s\u1ed1 v\u00f2ng v\u00e0 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua nh\u01b0 nhau. H\u1ecfi nam ch\u00e2m n\u00e0o h\u00fat mi\u1ebfng s\u1eaft m\u1ea1nh h\u01a1n ?","select":["A. C\u1ea3 a, b y\u1ebfu nh\u01b0 nhau.","B. H\u00ecnh A.","C. C\u1ea3 a, b m\u1ea1nh nh\u01b0 nhau.","D. H\u00ecnh b."],"hint":"","explain":"<span class='basic_left'>Do t\u1eeb tr\u01b0\u1eddng c\u1ee7a nam ch\u00e2m h\u00ecnh a l\u1edbn h\u01a1n (C\u00f3 \u0111\u1ea7u kh\u00f4ng nh\u1ecdn) =>L\u1ef1c t\u1eeb h\u00fat m\u1ea1nh h\u01a1n.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3146},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/vatly/bai25/lv2/img\/h15.jpg'\/><\/center>Mu\u1ed1n b\u1ea3o qu\u1ea3n t\u1eeb t\u00ednh c\u1ee7a nam ch\u00e2m ta ph\u1ea3i l\u00e0m g\u00ec ?","select":["A. B\u00f4i d\u1ea7u, m\u1ee1 v\u00e0o thanh nam ch\u00e2m.","B. D\u00f9ng v\u1eadt c\u00e1ch \u0111i\u1ec7n \u0111\u1ec3 g\u00f3i nam ch\u00e2m th\u00e0nh nhi\u1ec1u l\u1edbp.","C. \u0110\u1ec3 nam ch\u00e2m c\u00e1ch xa c\u00e1c v\u1eadt b\u1eb1ng s\u1eaft, th\u00e9p.","D. D\u00f9ng c\u00e1c thanh s\u1eaft non s\u1eafp x\u1ebfp nh\u01b0 h\u00ecnh 25.4."],"hint":"","explain":"<span class='basic_left'>Tu\u1ed5i c\u1ee7a nam ch\u00e2m c\u00f3 th\u1ec3 k\u00e9o d\u00e0i r\u1ea5t l\u00e2u (v\u00e0i ch\u1ee5c n\u0103m) n\u1ebfu b\u1ea3o qu\u1ea3n th\u00edch h\u1ee3p. M\u1ed9t khi v\u1eadt li\u1ec7u c\u00f3 t\u1eeb tr\u01b0\u1eddng v\u00e0 tr\u1edf th\u00e0nh nam ch\u00e2m th\u00ec \u0111\u00f3 c\u0169ng l\u00e0 m\u1ed9t c\u00e1ch t\u00edch l\u0169y n\u0103ng l\u01b0\u1ee3ng (n\u0103ng l\u01b0\u1ee3ng c\u1ee7a t\u1eeb tr\u01b0\u1eddng). \u0110\u1ec3 cho t\u1eeb t\u00ednh c\u1ee7a nam ch\u00e2m kh\u00f4ng b\u1ecb y\u1ebfu \u0111i th\u00ec ph\u1ea3i gi\u1eef sao cho t\u1eeb th\u00f4ng c\u1ee7a n\u00f3 kh\u00f4ng b\u1ecb ph\u00e1t t\u00e1n ra kh\u00f4ng kh\u00ed. V\u1eady th\u00ec c\u1ea7n ph\u1ea3i n\u1ed1i li\u1ec1n c\u00e1c \u0111\u01b0\u1eddng s\u1ee9c t\u1eeb b\u1eb1ng s\u1eaft m\u1ec1m, \u0111\u1ec3 c\u00e1c \u0111\u01b0\u1eddng s\u1ee9c kh\u00e9p k\u00edn qua s\u1eaft, \u0111i th\u00f4ng su\u1ed1t t\u1eeb c\u1ef1c b\u1eafc \u0111\u1ebfn c\u1ef1c nam.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":3147},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"L\u00f5i s\u1eaft trong nam ch\u00e2m \u0111i\u1ec7n c\u00f3 t\u00e1c d\u1ee5ng g\u00ec ?","select":["A. L\u00e0m cho nam ch\u00e2m \u0111\u01b0\u1ee3c ch\u1eafc ch\u1eafn.","B. Kh\u00f4ng c\u00f3 t\u00e1c d\u1ee5ng g\u00ec.","C. L\u00e0m t\u0103ng t\u1eeb tr\u01b0\u1eddng c\u1ee7a \u1ed1ng d\u00e2y.","D. L\u00e0m nam ch\u00e2m \u0111\u01b0\u1ee3c nhi\u1ec5m t\u1eeb v\u0129nh vi\u1ec5n."],"hint":"","explain":"<span class='basic_left'>L\u00f5i s\u1eaft trong nam ch\u00e2m \u0111i\u1ec7n c\u00f3 t\u00e1c d\u1ee5ng l\u00e0m t\u0103ng t\u1eeb tr\u01b0\u1eddng c\u1ee7a \u1ed1ng d\u00e2y. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3148},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Nh\u1eadn x\u00e9t v\u1ec1 t\u00e1c d\u1ee5ng t\u1eeb c\u1ee7a \u1ed1ng d\u00e2y c\u00f3 l\u00f5i s\u1eaft non v\u00e0 \u1ed1ng d\u00e2y c\u00f3 l\u00f5i th\u00e9p khi ng\u1eaft d\u00f2ng \u0111i\u1ec7n qua \u1ed1ng d\u00e2y.","select":["A. L\u00f5i s\u1eaft non m\u1ea5t h\u1ebft t\u1eeb t\u00ednh c\u00f2n l\u00f5i th\u00e9p th\u00ec v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh, khi ng\u1eaft d\u00f2ng \u0111i\u1ec7n \u0111i qua \u1ed1ng d\u00e2y.","B. L\u00f5i th\u00e9p m\u1ea5t h\u1ebft t\u1eeb t\u00ednh c\u00f2n l\u00f5i s\u1eaft non th\u00ec v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh, khi ng\u1eaft d\u00f2ng \u0111i\u1ec7n \u0111i qua \u1ed1ng d\u00e2y.","C. C\u1ea3 l\u00f5i th\u00e9p v\u00e0 l\u00f5i s\u1eaft non \u0111\u1ec1u m\u1ea5t h\u1ebft t\u1eeb t\u00ednh.","D. C\u1ea3 l\u00f5i th\u00e9p v\u00e0 l\u00f5i s\u1eaft non \u0111\u1ec1u c\u00f2n t\u1eeb t\u00ednh."],"hint":"","explain":"<span class='basic_left'>L\u00f5i s\u1eaft non m\u1ea5t h\u1ebft t\u1eeb t\u00ednh c\u00f2n l\u00f5i th\u00e9p th\u00ec v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh, khi ng\u1eaft d\u00f2ng \u0111i\u1ec7n \u0111i qua \u1ed1ng d\u00e2y. V\u00ec th\u00e9p c\u00f3 kh\u1ea3 n\u0103ng b\u1ecb nhi\u1ec5m t\u1eeb, n\u00f3 v\u1eabn gi\u1eef tr\u1ea1ng th\u00e1i b\u1ecb nhi\u1ec5m t\u1eeb ngay khi kh\u00f4ng c\u00f2n d\u00f2ng \u0111i\u1ec7n.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":3149},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"Mu\u1ed1n nam ch\u00e2m \u0111i\u1ec7n m\u1ea5t h\u1ebft t\u1eeb t\u00ednh th\u00ec l\u00e0m th\u1ebf n\u00e0o?","select":["A. Mu\u1ed1n nam ch\u00e2m \u0111i\u1ec7n m\u1ea5t h\u1ebft t\u1eeb t\u00ednh ta ch\u1ec9 c\u1ea7n ng\u1eaft d\u00f2ng \u0111i\u1ec7n \u0111\u1ec3 d\u00f2ng \u0111i\u1ec7n kh\u00f4ng ch\u1ea1y qua \u1ed1ng d\u00e2y.","B. T\u0103ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u1ed1ng d\u00e2y.","C. Thay l\u00f5i s\u1eaft non b\u1eb1ng l\u00f5i niken.","D. C\u1ea3 3 \u0111\u00e1p \u00e1n tr\u00ean \u0111\u1ec1u sai."],"hint":"","explain":"<span class='basic_left'>Mu\u1ed1n nam ch\u00e2m \u0111i\u1ec7n m\u1ea5t h\u1ebft t\u1eeb t\u00ednh ta ch\u1ec9 c\u1ea7n ng\u1eaft d\u00f2ng \u0111i\u1ec7n \u0111\u1ec3 d\u00f2ng \u0111i\u1ec7n kh\u00f4ng ch\u1ea1y qua \u1ed1ng d\u00e2y.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":3150}],"lesson":{"save":0,"level":2}}