{"segment":[{"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":"\u0110\u1eb7t m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 3V v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn b\u1eb1ng h\u1ee3p kim th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn n\u00e0y l\u00e0 0,2A. H\u1ecfi n\u1ebfu t\u0103ng th\u00eam 12V n\u1eefa th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 c\u00f3 gi\u00e1 tr\u1ecb n\u00e0o d\u01b0\u1edbi \u0111\u00e2y:","select":["A. 0,6A.","B. 0,8A.","C. 1A.","D. M\u1ed9t gi\u00e1 tr\u1ecb kh\u00e1c c\u00e1c gi\u00e1 tr\u1ecb tr\u00ean."],"hint":"","explain":"<span class='basic_left'>v\u00ec $R=\\dfrac{U}{I}=\\dfrac{3}{0,2}=15\\Omega $ <br\/>Khi t\u0103ng th\u00eam 12V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n khi \u0111\u00f3 l\u00e0:<br\/> $I=\\dfrac{U}{R}=\\dfrac{3+12}{15}=1A$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3031},{"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":"\u0110\u1eb7t m\u1ed9t H\u0110T U v\u00e0o hai \u0111\u1ea7u c\u00e1c d\u00e2y d\u1eabn kh\u00e1c nhau v\u00e0 \u0111o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n I ch\u1ea1y qua m\u1ed7i d\u00e2y d\u1eabn \u0111\u00f3. C\u00e2u ph\u00e1t bi\u1ec3u n\u00e0o d\u01b0\u1edbi \u0111\u00e2y l\u00e0 \u0111\u00fang khi t\u00ednh th\u01b0\u01a1ng s\u1ed1 $\\dfrac{U}{I}$ cho m\u1ed7i d\u00e2y d\u1eabn? ","select":["A. Th\u01b0\u01a1ng s\u1ed1 n\u00e0y c\u00f3 gi\u00e1 tr\u1ecb nh\u01b0 nhau \u0111\u1ed1i v\u1edbi c\u00e1c d\u00e2y d\u1eabn.","B. Th\u01b0\u01a1ng s\u1ed1 n\u00e0y c\u00f3 gi\u00e1 tr\u1ecb c\u00e0ng l\u1edbn \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn n\u00e0o th\u00ec d\u00e2y d\u1eabn \u0111\u00f3 c\u00f3 \u0111i\u1ec7n tr\u1edf c\u00e0ng l\u1edbn.","C. Th\u01b0\u01a1ng s\u1ed1 n\u00e0y c\u00f3 gi\u00e1 tr\u1ecb c\u00e0ng l\u1edbn \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn n\u00e0o th\u00ec d\u00e2y d\u1eabn \u0111\u00f3 c\u00f3 \u0111i\u1ec7n tr\u1edf c\u00e0ng nh\u1ecf.","D. Th\u01b0\u01a1ng s\u1ed1 n\u00e0y kh\u00f4ng c\u00f3 gi\u00e1 tr\u1ecb x\u00e1c \u0111\u1ecbnh \u0111\u1ed1i v\u1edbi m\u1ed7i d\u00e2y d\u1eabn."],"hint":"","explain":"<span class='basic_left'>Th\u01b0\u01a1ng s\u1ed1 n\u00e0y c\u00f3 gi\u00e1 tr\u1ecb c\u00e0ng l\u1edbn \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn n\u00e0o th\u00ec d\u00e2y d\u1eabn \u0111\u00f3 c\u00f3 \u0111i\u1ec7n tr\u1edf c\u00e0ng l\u1edbn.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3032},{"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":"\u0110i\u1ec7n tr\u1edf ${{R}_{1}}=30\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t l\u00e0 2A v\u00e0 \u0111i\u1ec7n tr\u1edf ${{R}_{2}}=10\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t l\u00e0 1A. C\u00f3 th\u1ec3 m\u1eafc n\u1ed1i ti\u1ebfp hai \u0111i\u1ec7n tr\u1edf n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf (H\u0110T) n\u00e0o d\u01b0\u1edbi \u0111\u00e2y?","select":["A. 80V, v\u00ec \u0111i\u1ec7n tr\u1edf t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u1ee7a m\u1ea1ch l\u00e0 40\u2126 v\u00e0 ch\u1ecbu \u0111\u1ef1ng d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t 2A.","B. 70V, v\u00ec \u0111i\u1ec7n tr\u1edf ${{R}_{1}}$ ch\u1ecbu \u0111\u01b0\u1ee3c H\u0110T l\u1edbn nh\u1ea5t 60V, \u0111i\u1ec7n tr\u1edf ${{R}_{2}}$ ch\u1ecbu \u0111\u01b0\u1ee3c 10V.","C. 120V, v\u00ec \u0111i\u1ec7n tr\u1edf t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u1ee7a m\u1ea1ch l\u00e0 40\u2126 v\u00e0 ch\u1ecbu \u0111\u1ef1ng d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 t\u1ed5ng c\u1ed9ng 3A.","D. 40V, v\u00ec \u0111i\u1ec7n tr\u1edf t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u1ee7a m\u1ea1ch l\u00e0 40\u2126 v\u00e0 ch\u1ecbu \u0111\u1ef1ng d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 1A."],"hint":"","explain":"<span class='basic_left'>70V, v\u00ec \u0111i\u1ec7n tr\u1edf ${{R}_{1}}$ ch\u1ecbu \u0111\u01b0\u1ee3c hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t 60V, \u0111i\u1ec7n tr\u1edf ${{R}_{2}}$ ch\u1ecbu \u0111\u01b0\u1ee3c 10V.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":1}]}],"id_ques":3033},{"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":"\u0110i\u1ec7n tr\u1edf ${{R}_{1}}=30\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t l\u00e0 2A v\u00e0 \u0111i\u1ec7n tr\u1edf ${{R}_{2}}=10\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t l\u00e0 1A. C\u00f3 th\u1ec3 m\u1eafc song song hai \u0111i\u1ec7n tr\u1edf n\u00e0y v\u00e0o H\u0110T n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? ","select":["A. 10V.","B. 22,5V.","C. 60V.","D. 15V."],"hint":"","explain":"<span class='basic_left'>V\u00ec ${{U}_{1}}={{I}_{1}}\\times {{R}_{1}}=2\\times 30=60V$ , ${{U}_{2}}={{I}_{2}}\\times {{R}_{2}}=1\\times 10=10V$<br\/>Do hai \u0111i\u1ec7n tr\u1edf n\u00e0y m\u1eafc song song v\u1edbi nhau n\u00ean ch\u00fang s\u1ebd c\u00f3 hi\u1ec7u \u0111i\u1ec7n th\u1ebf b\u1eb1ng nhau, m\u00e0 \u0111i\u1ec7n tr\u1edf ${{R}_{2}}$ ch\u1ecbu hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t l\u00e0 10V n\u00ean ta ch\u1ecdn \u0111\u00e1p \u00e1n A<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":3034},{"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":"M\u1ed9t b\u1ebfp \u0111i\u1ec7n lo\u1ea1i 220V-1000W \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V \u0111\u1ec3 \u0111un s\u00f4i 2l n\u01b0\u1edbc c\u00f3 nhi\u1ec7t \u0111\u1ed9 ban \u0111\u1ea7u $25{}^\\circ C$. Hi\u1ec7u su\u1ea5t c\u1ee7a qu\u00e1 tr\u00ecnh \u0111un l\u00e0 85%.bi\u1ebft nhi\u1ec7t dung ri\u00eang c\u1ee7a n\u01b0\u1edbc l\u00e0 4200 J\/kg.K. N\u1ebfu g\u1eadp \u0111\u00f4i d\u00e2y \u0111i\u1ec7n tr\u1edf c\u1ee7a b\u1ebfp n\u00e0y v\u00e0 v\u1eabn s\u1eed d\u1ee5ng hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V th\u00ec th\u1eddi gian \u0111un s\u00f4i 2l n\u01b0\u1edbc c\u00f3 nhi\u1ec7t \u0111\u1ed9 ban \u0111\u1ea7u v\u00e0 hi\u1ec7u su\u1ea5t nh\u01b0 tr\u00ean l\u00e0 bao nhi\u00eau? ","select":["A. 370s.","B. 120s.","C. 74s.","D. 185s."],"hint":"","explain":"<span class='basic_left'>Nhi\u1ec7t l\u01b0\u1ee3ng c\u1ea7n thi\u1ebft \u0111\u1ec3 \u0111un s\u00f4i 2 l\u00edt n\u01b0\u1edbc \u1edf nhi\u1ec7t \u0111\u1ed9 ban \u0111\u1ea7u $25{}^\\circ C$ l\u00e0:<br\/>${{Q}_{i}}=m\\times c\\times \\left( {{t}_{2}}-{{t}_{1}} \\right)=2\\times 4200\\times \\left( 100-25 \\right)=630000J=630KJ$<br\/> Nhi\u1ec7t l\u01b0\u1ee3ng b\u1ebfp t\u1ecfa ra l\u00e0: $Q=\\dfrac{{{Q}_{i}}}{H}=741176,5J$ <br\/>V\u1eady th\u1eddi gian c\u1ea7n thi\u1ebft \u0111\u1ec3 \u0111un s\u00f4i 2 l\u00edt n\u01b0\u1edbc trong \u0111i\u1ec1u ki\u1ec7n tr\u00ean l\u00e0: <br\/>$t=\\dfrac{Q}{P}=741s$ <br\/>Do g\u1eadp \u0111\u00f4i d\u00e2y \u0111i\u1ec7n tr\u1edf v\u00e0 v\u1eabn s\u1eed d\u1ee5ng hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V n\u00ean : <br\/>Ti\u1ebft di\u1ec7n t\u0103ng 2 l\u1ea7n n\u00ean \u0110i\u1ec7n tr\u1edf gi\u1ea3m 2 l\u1ea7n. <br\/>Chi\u1ec1u d\u00e0i gi\u1ea3m 2 l\u1ea7n n\u00ean \u0111i\u1ec7n tr\u1edf gi\u1ea3m 2 l\u1ea7n. <br\/>V\u1eady \u0111i\u1ec7n tr\u1edf gi\u1ea3m 4 l\u1ea7n.<br\/>Th\u1eddi gian c\u1ea7n \u0111\u1ec3 \u0111un s\u00f4i 2l n\u01b0\u1edbc khi \u0111\u00f3 c\u0169ng s\u1ebd gi\u1ea3m 4 l\u1ea7n:<br\/>$t=\\dfrac{T}{4}=\\dfrac{741}{4}=185s$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":3035},{"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":"M\u1ed9t khu d\u00e2n c\u01b0 s\u1eed d\u1ee5ng c\u00f4ng su\u1ea5t \u0111i\u1ec7n trung b\u00ecnh l\u00e0 4,95 kW v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V. D\u00e2y t\u1ea3i \u0111i\u1ec7n t\u1eeb tr\u1ea1m cung c\u1ea5p t\u1edbi khu d\u00e2n c\u01b0 n\u00e0y c\u00f3 \u0111i\u1ec7n tr\u1edf t\u1ed5ng c\u1ed9ng l\u00e0 0,4. T\u00ednh ti\u1ec1n \u0111i\u1ec7n m\u00e0 khu n\u00e0y ph\u1ea3i tr\u1ea3 trong m\u1ed9t th\u00e1ng ( 30 ng\u00e0y), bi\u1ebft r\u1eb1ng th\u1eddi gian d\u00f9ng \u0111i\u1ec7n trong m\u1ed9t ng\u00e0y trung b\u00ecnh l\u00e0 6 gi\u1edd, v\u00e0 gi\u00e1 \u0111i\u1ec7n l\u00e0 700 \u0111\u1ed3ng m\u1ed7i kWh.","select":["A. 891 \u0111\u1ed3ng","B. 918 \u0111\u1ed3ng","C. 623700 \u0111\u1ed3ng","D. 672300 \u0111\u1ed3ng"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y t\u1ea3i \u0111i\u1ec7n l\u00e0: <br\/>$I=\\dfrac{P}{U}=22,5A$ <br\/>L\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng ti\u00eau th\u1ee5 trong 30 ng\u00e0y l\u00e0: <br\/>$A=P\\times t=4,95\\times 6 \\times 30=891k\\text{W}h$<br\/> Ti\u1ec1n \u0111i\u1ec7n ph\u1ea3i tr\u1ea3 trong 30 ng\u00e0y l\u00e0 :<br\/>$T'=A\\times T=891\\times 700=623700$ \u0111\u1ed3ng<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3036},{"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\u1ec1n t\u1eeb th\u00edch h\u1ee3p v\u00e0o ch\u1ed7 tr\u1ed1ng:<br\/>...... d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ed9t d\u00e2y d\u1eabn t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn v\u00e0 t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi \u0111i\u1ec7n tr\u1edf d\u00e2y.","select":["A. \u0110i\u1ec7n t\u00edch. ","B. \u0110i\u1ec7n l\u01b0\u1ee3ng.","C. Hi\u1ec7u \u0111i\u1ec7n th\u1ebf.","D. C\u01b0\u1eddng \u0111\u1ed9."],"hint":"","explain":"<span class='basic_left'>\u0110\u00e2y l\u00e0 n\u1ed9i dung \u0111\u1ecbnh lu\u1eadt \u00d4m, ta ph\u1ea3i ch\u1ecdn t\u1eeb c\u01b0\u1eddng \u0111\u1ed9. C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ed9t d\u00e2y d\u1eabn t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn v\u00e0 t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi \u0111i\u1ec7n tr\u1edf d\u00e2y.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":3037},{"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":"C\u00f4ng th\u1ee9c bi\u1ec3u th\u1ecb \u0111\u1ecbnh lu\u1eadt \u00d4m l\u00e0: ","select":["A. $R=\\dfrac{U}{I}$","B. $I=\\dfrac{R}{U}$","C. $I=\\dfrac{U}{R}$","D. $R=\\dfrac{U}{I}$"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng th\u1ee9c bi\u1ec3u th\u1ecb \u0111\u1ecbnh lu\u1eadt \u00d4m l\u00e0 $I=\\dfrac{U}{R}$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3038},{"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":"Cho \u0111i\u1ec7n tr\u1edf ${{R}_{1}}=100\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n t\u1ed1i \u0111a l\u00e0 0,6A v\u00e0 \u0111i\u1ec7n tr\u1edf ${{R}_{2}}=50\\Omega $ ch\u1ecbu \u0111\u01b0\u1ee3c c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n t\u1ed1i \u0111a l\u00e0 0,4A. C\u00f3 th\u1ec3 m\u1eafc n\u1ed1i ti\u1ebfp hai \u0111i\u1ec7n tr\u1edf tr\u00ean v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf t\u1ed1i \u0111a l\u00e0: ","select":["A. U = 80V.","B. U = 60V.","C. U = 90V.","D. U = 30V."],"hint":"","explain":"<span class='basic_left'>N\u1ebfu m\u1eafc n\u1ed1i ti\u1ebfp hai \u0111i\u1ec7n tr\u1edf th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n t\u1ed1i \u0111a l\u00e0 0,4A<br\/>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf t\u1ed1i \u0111a l\u00e0:$U=I\\times \\left( {{R}_{1}}+{{R}_{2}} \\right)=0,4\\times \\left( 100+50 \\right)=60V$ .<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3039},{"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":"Khi \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 12V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua n\u00f3 l\u00e0 0,6A. N\u1ebfu c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 l\u00e0 1A th\u00ec hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn l\u00e0: ","select":["A. 12V.","B. 9V.","C. 20V.","D. 18V."],"hint":"","explain":"<span class='basic_left'>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u d\u00e2y d\u1eabn t\u0103ng bao nhi\u00eau l\u1ea7n th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn \u0111\u00f3 c\u0169ng t\u0103ng b\u1ea5y nhi\u00eau l\u1ea7n.<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u0169ng t\u0103ng l\u00ean $\\dfrac{5}{3}$ l\u1ea7n n\u00ean hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o d\u00e2y d\u1eabn \u0111\u00e3 t\u0103ng l\u00ean $\\dfrac{5}{3}$ l\u1ea7n $U'=U\\times \\dfrac{5}{3}=20V$ .<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3040},{"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":"M\u1ed9t m\u1ea1ch \u0111i\u1ec7n g\u1ed3m 3 \u0111i\u1ec7n tr\u1edf ${{R}_{1}}=2\\Omega $, ${{R}_{2}}=5\\Omega $, ${{R}_{3}}=3\\Omega $, m\u1eafc n\u1ed1i ti\u1ebfp. C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y trong m\u1ea1ch l\u00e0 1,2A. Hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ea7u m\u1ea1ch U l\u00e0: ","select":["A. 10V.","B. 11V.","C. 12V.","D. 13V."],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf m\u1ea1ch $R={{R}_{1}}+{{R}_{2}}+{{R}_{3}}=2+5+3=10\\Omega $ <br\/>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf hai \u0111\u1ea7u m\u1ea1ch U l\u00e0: $U=I\\times R=1,2\\times 10=12V$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3041},{"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":"Hai \u0111i\u1ec7n tr\u1edf ${{R}_{1}}=3\\Omega $, ${{R}_{2}}=2\\Omega $ m\u1eafc n\u1ed1i ti\u1ebfp; c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua m\u1ea1ch l\u00e0 0,12A. N\u1ebfu m\u1eafc song song hai \u0111i\u1ec7n tr\u1edf tr\u00ean v\u00e0o m\u1ea1ch th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n l\u00e0: ","select":["A. 1,2A.","B. 1A.","C. 0,5A .","D. 1,8A."],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf m\u1ea1ch n\u1ed1i ti\u1ebfp $R={{R}_{1}}+{{R}_{2}}=3+2=5\\Omega $.<br\/>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf hai \u0111\u1ea7u m\u1ea1ch U l\u00e0: $U=I\\times R=0,12\\times 5=0,6V$<br\/>\u0110i\u1ec7n tr\u1edf m\u1ea1ch song song $R=\\dfrac{{{R}_{1}}{{R}_{2}}}{{{R}_{1}}+{{R}_{2}}}=\\dfrac{3\\times 2}{3+2}=1,2\\Omega $ <br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I=\\dfrac{U}{R}=\\dfrac{0,6}{1,2}=0,5A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3042},{"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":"Cho hai \u0111i\u1ec7n tr\u1edf ${{R}_{1}}$ v\u00e0 ${{R}_{2}}$, bi\u1ebft ${{R}_{2}}=3{{R}_{1}}$ v\u00e0${{R}_{1}}=15\\Omega $. Khi m\u1eafc hai \u0111i\u1ec7n tr\u1edf n\u00e0y n\u1ed1i ti\u1ebfp v\u00e0o hai \u0111i\u1ec3m c\u00f3 hi\u1ec7u \u0111i\u1ec7n th\u1ebf 120V th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u00e0: ","select":["A. 2A.","B. 2,5A.","C. 4A.","D. 0,4A."],"hint":"","explain":"<span class='basic_left'>Ta c\u00f3 ${{R}_{2}}=3{{R}_{1}}=3\\times 15=45\\Omega $.<br\/>\u0110i\u1ec7n tr\u1edf m\u1ea1ch l\u00e0$R={{R}_{1}}+{{R}_{2}}=15+45=60\\Omega $.<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I=\\dfrac{U}{R}=\\dfrac{120}{60}=2A$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":3043},{"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\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ed9t b\u00f3ng \u0111\u00e8n l\u00e0 1,2A khi m\u1eafc n\u00f3 v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 12V. Mu\u1ed1n c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua b\u00f3ng \u0111\u00e8n t\u0103ng th\u00eam 0,3A th\u00ec hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u b\u00f3ng \u0111\u00e8n t\u0103ng ho\u1eb7c gi\u1ea3m bao nhi\u00eau? ","select":["A. T\u0103ng 5V.","B. T\u0103ng 3V.","C. Gi\u1ea3m 3V.","D. Gi\u1ea3m 2V."],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ecbnh lu\u1eadt \u00d4m ta c\u00f3 \u0111i\u1ec7n tr\u1edf b\u00f3ng \u0111\u00e8n: $R=\\dfrac{U}{I}=\\dfrac{12}{1,2}=10\\Omega $.<br\/>Khi t\u0103ng th\u00eam c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n l\u00e0 I\u2019 = 1,5A, v\u1eady$U'=1,5\\times 10=15\\Omega $.<br\/>V\u1eady ta ph\u1ea3i t\u0103ng U th\u00eam $\\Delta U=U'-U=15-12=3V$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3044},{"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":"M\u1ed9t d\u00e2y d\u1eabn c\u00f3 \u0111i\u1ec7n tr\u1edf 50\u03a9 ch\u1ecbu \u0111\u01b0\u1ee3c d\u00f2ng \u0111i\u1ec7n c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u1edbn nh\u1ea5t l\u00e0 300mA. Hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t \u0111\u1eb7t gi\u1eefa hai \u0111\u1ea7u d\u00e2y d\u1eabn l\u00e0: ","select":["A. 1500V.","B. 15V.","C. 60V.","D. 6V."],"hint":"","explain":"<span class='basic_left'>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t $U=I\\times R=0,3\\times 50=15V$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3045},{"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":"Mu\u1ed1n \u0111o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua v\u1eadt d\u1eabn c\u1ea7n c\u00e1c d\u1ee5ng c\u1ee5 g\u00ec v\u00e0 m\u1eafc d\u1ee5ng c\u1ee5 \u0111\u00f3 v\u1edbi v\u1eadt c\u1ea7n \u0111o l\u00e0: ","select":["A. \u0110i\u1ec7n k\u1ebf m\u1eafc song song v\u1edbi v\u1eadt c\u1ea7n \u0111o.","B. V\u00f4n k\u1ebf m\u1eafc n\u1ed1i ti\u1ebfp v\u1edbi v\u1eadt c\u1ea7n \u0111o.","C. Ampe k\u1ebf m\u1eafc n\u1ed1i ti\u1ebfp v\u1edbi v\u1eadt c\u1ea7n \u0111o.","D. Ampe k\u1ebf m\u1eafc song song v\u1edbi v\u1eadt c\u1ea7n \u0111o."],"hint":"","explain":"<span class='basic_left'>Mu\u1ed1n \u0111o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u1ea7n m\u1eafc ampe k\u1ebf n\u1ed1i ti\u1ebfp v\u1edbi v\u1eadt c\u1ea7n \u0111o.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":1}]}],"id_ques":3046},{"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":"M\u1ed9t d\u00e2y d\u1eabn d\u00e0i 120m \u0111\u01b0\u1ee3c u\u1ed1n th\u00e0nh m\u1ed9t cu\u1ed9n d\u00e2y. Khi \u0111\u1eb7t m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 30V v\u00e0o hia \u0111\u1ea7u cu\u1ed9n d\u00e2y n\u00e0y th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua n\u00f3 l\u00e0 125mA. M\u1ed7i \u0111o\u1ea1n d\u00e2y d\u00e0i 1m s\u1ebd c\u00f3 \u0111i\u1ec7n tr\u1edf l\u00e0: ","select":["A. 1\u03a9.","B. 2\u03a9.","C. 3\u03a9.","D. 4\u03a9."],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf cu\u1ed9n d\u00e2y$R=\\dfrac{U}{I}=\\dfrac{30}{0,125}=240\\Omega $.<br\/>\u0110i\u1ec7n tr\u1edf m\u1ed7i \u0111o\u1ea1n d\u00e2y d\u00e0i 1m: ${{R}_{1}}=\\dfrac{240}{120}=2\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3047},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[4]],"list":[{"point":5,"ques":"M\u1ed9t \u0111o\u1ea1n m\u1ea1ch \u0111i\u1ec7n g\u1ed3m hai \u0111i\u1ec7n tr\u1edf${{R}_{1}}=6\\Omega $, ${{R}_{2}}=3\\Omega$ m\u1eafc song song v\u1edbi nhau v\u00e0o hai \u0111i\u1ec3m c\u00f3 hi\u1ec7u \u0111i\u1ec7n th\u1ebf 6V. \u0110i\u1ec7n tr\u1edf t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u00e0 c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ea1ch ch\u00ednh l\u00e0: ","select":["A. R = 9\u03a9 v\u00e0 I = 0,6A.","B. R = 9\u03a9 v\u00e0 I = 1A.","C. R = 2\u03a9 v\u00e0 I = 1A.","D. R = 2\u03a9 v\u00e0 I = 3A."],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf m\u1ea1ch m\u1eafc song song $R=\\dfrac{{{R}_{1}}\\times {{R}_{2}}}{{{R}_{1}}+{{R}_{2}}}=\\dfrac{6\\times 3}{6+3}=2\\Omega $ <br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I=\\dfrac{U}{R}=\\dfrac{6}{2}=3A$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":3048},{"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":"Khi \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 9V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua n\u00f3 l\u00e0 0,6A. N\u1ebfu hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn t\u0103ng l\u00ean \u0111\u1ebfn 15V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 l\u00e0: ","select":["A. 1,2A.","B. 1A.","C. 0,9A.","D. 1,8A."],"hint":"","explain":"<span class='basic_left'>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u d\u00e2y d\u1eabn t\u0103ng bao nhi\u00eau l\u1ea7n th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn \u0111\u00f3 c\u0169ng t\u0103ng b\u1ea5y nhi\u00eau l\u1ea7n.<br\/>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o d\u00e2y d\u1eabn \u0111\u00e3 t\u0103ng l\u00ean 5\/3 l\u1ea7n n\u00ean c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u0169ng t\u0103ng l\u00ean $\\dfrac{5}{3}$ l\u1ea7n $I'=I\\times \\dfrac{5}{3}=1A$ .<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":3049},{"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":"M\u1ed9t d\u00e2y \u0111i\u1ec7n tr\u1edf c\u00f3 chi\u1ec1u d\u00e0i 12m v\u00e0 c\u00f3 \u0111i\u1ec7n tr\u1edf 36\u03a9. \u0110i\u1ec7n tr\u1edf d\u00e2y d\u1eabn khi c\u1eaft ng\u1eafn d\u00e2y \u0111i 2m l\u00e0: ","select":["A. 10\u03a9.","B. 20\u03a9.","C. 30\u03a9.","D. 40\u03a9."],"hint":"","explain":"<span class='basic_left'>C\u1eaft ng\u1eafn d\u00e2y \u0111i 2m th\u00ec 10m d\u00e2y c\u00f2n l\u1ea1i c\u00f3 \u0111i\u1ec7n tr\u1edf: $R=10\\times \\dfrac{36}{12}=30\\Omega $. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":3050}],"lesson":{"save":0,"level":2}}