{"segment":[{"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 \u0111i\u1ec7n tr\u1edf R = 15\u03a9. Khi m\u1eafc \u0111i\u1ec7n tr\u1edf n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 6V th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u00e0 bao nhi\u00eau?","select":["A. 0,4A","B. 0,2A","C. 0,04A","D. 4A"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ea1ch l\u00e0: $I=\\dfrac{U}{R}=0,4A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2731},{"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/bai2/lv2/img\/h2.jpg'\/><\/center>D\u1ef1a v\u00e0o \u0111\u1ed3 th\u1ecb \u1edf d\u01b0\u1edbi h\u00e3y t\u00ednh \u0111i\u1ec7n tr\u1edf c\u1ee7a v\u1eadt d\u1eabn n\u1ebfu b\u1ecf qua nh\u1eefng sai s\u1ed1 trong ph\u00e9p \u0111o.","select":["A. 10\u03a9","B. 15\u03a9","C. 3\u03a9","D. 5\u03a9"],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ed3 th\u1ecb 2.1 ta th\u1ea5y. khi U=4,5V th\u00ec I=0,9A, suy ra: $R=\\dfrac{U}{I}=5\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2732},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[1]],"list":[{"point":5,"ques":"\u0110\u01a1n v\u1ecb n\u00e0o d\u01b0\u1edbi \u0111\u00e2y l\u00e0 \u0111\u01a1n v\u1ecb c\u1ee7a \u0111i\u1ec7n tr\u1edf?","select":["A. \u00d4m","B. O\u00e1t","C. V\u00f4n","D. Ampe"],"hint":"","explain":"<span class='basic_left'>\u0110\u01a1n v\u1ecb c\u1ee7a \u0111i\u1ec7n tr\u1edf l\u00e0 \u00d4m ($\\Omega $) <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2733},{"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 = 15 \u03a9 m\u1eafc \u0111i\u1ec7n tr\u1edf n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 6V. Mu\u1ed1n c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua \u0111i\u1ec7n tr\u1edf t\u0103ng th\u00eam 0,3A so v\u1edbi tr\u01b0\u1eddng h\u1ee3p tr\u00ean th\u00ec hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u \u0111i\u1ec7n tr\u1edf khi \u0111\u00f3 l\u00e0 bao nhi\u00eau?","select":["A. 10V","B. 10,5V","C. 5V","D. 7V"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ea1ch: $I=\\dfrac{U}{R}=\\dfrac{6}{15}=0,4A$<br\/> C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n sau khi t\u0103ng them 0,3A l\u00e0: $I'=I+0,3=0,7A$ <br\/>Khi \u0111\u00f3 hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u \u0111i\u1ec7n tr\u1edf l\u00e0: $U=I\\times R=0,7\\times 15=10,5A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2734},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/vatly/bai2/lv2/img\/h5.jpg'\/><\/center>Cho m\u1ea1ch \u0111i\u1ec7n c\u00f3 s\u01a1 \u0111\u1ed3 nh\u01b0 h\u00ecnh 2.2, \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$=10\u03a9, hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u \u0111o\u1ea1n m\u1ea1ch l\u00e0 ${{U}_{MN}}=12V$. T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I_{1}^{{}}$ ch\u1ea1y qua $R_{1}^{{}}$:","select":["A. 1,2A","B. 2,4A","C. 1A","D. 2A"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I_{1}^{{}}$ch\u1ea1y qua$R_{1}^{{}}$: <br\/>${{I}_{1}}=\\dfrac{{{U}_{MN}}}{{{R}_{1}}}=\\dfrac{12}{10}=1,2A$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2735},{"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":"\u0110i\u1ec7n tr\u1edf c\u1ee7a m\u1ed9t d\u00e2y d\u1eabn nh\u1ea5t \u0111\u1ecbnh c\u00f3 m\u1ed1i quan h\u1ec7 ph\u1ee5 thu\u1ed9c n\u00e0o d\u01b0\u1edbi \u0111\u00e2y? ","select":["A. 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.","B. T\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn.","C. Kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e1o hai \u0111\u1ea7u d\u00e2y d\u1eabn.","D. Gi\u1ea3m khi c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn gi\u1ea3m"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a m\u1ed9t d\u00e2y d\u00e0n nh\u1ea5t \u0111\u1ecbnh kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e1o hai \u0111\u1ea7u d\u00e2y d\u1eabn m\u00e0 ch\u1ec9 ph\u1ee5 thu\u1ed9c v\u00e0o b\u1ea3n ch\u1ea5t d\u00e2y d\u1eabn. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":1}]}],"id_ques":2736},{"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":"Gi\u1eefa hai \u0111\u1ea7u m\u1ed9t \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}=20\u03a9$ c\u00f3 m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u00e0 U = 3,2V. T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I_{1}^{{}}$ \u0111i qua \u0111i\u1ec7n tr\u1edf n\u00e0y.","select":["A. 0,16A","B. 0,1A ","C. 0,2A","D. 0,15A"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua \u0111i\u1ec7n tr\u1edf:<br\/>$I_{1}^{{}}=\\dfrac{U}{R_{1}^{{}}}=\\dfrac{3,2}{20}=0,16A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2737},{"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 m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf U v\u00e0o hai \u0111\u1ea7u m\u1ed9t \u0111i\u1ec7n tr\u1edf R th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u00e0 I. H\u1ec7 th\u1ee9c n\u00e0o d\u01b0\u1edbi \u0111\u00e2y bi\u1ec3u th\u1ecb \u0111\u1ecbnh lu\u1eadt \u00d4m ?","select":["A. $U=\\dfrac{I}{R}$","B. $I=\\dfrac{U}{R}$","C. $I=\\dfrac{R}{U}$","D. $R=\\dfrac{U}{I}$"],"hint":"","explain":"<span class='basic_left'><br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2738},{"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 th\u00ed nghi\u1ec7m kh\u1ea3o s\u00e1t \u0111\u1ecbnh lu\u1eadt \u00d4m, c\u00f3 th\u1ec3 l\u00e0m thay \u0111\u1ed5i \u0111\u1ea1i l\u01b0\u1ee3ng n\u00e0o trong s\u1ed1 c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng g\u1ed3m hi\u1ec7u \u0111i\u1ec7n th\u1ebf, c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n, \u0111i\u1ec7n tr\u1edf d\u00e2y d\u1eabn?","select":["A. Ch\u1ec9 thay \u0111\u1ed5i hi\u1ec7u \u0111i\u1ec7n th\u1ebf.","B. Ch\u1ec9 thay \u0111\u1ed5i c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n","C. Ch\u1ec9 thay \u0111\u1ed5i \u0111i\u1ec7n tr\u1edf d\u00e2y d\u1eabn","D. C\u1ea3 ba \u0111\u1ea1i l\u01b0\u1ee3ng tr\u00ean"],"hint":"","explain":"<span class='basic_left'>V\u00ec \u0111i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y d\u1eabn lu\u00f4n kh\u00f4ng thay \u0111\u1ed5i, ch\u1ec9 c\u00f3 th\u1ec3 thay \u0111\u1ed5i hi\u1ec7u \u0111i\u1ec7n th\u1ebf r\u1ed3i \u0111o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n theo t\u1eebng hi\u1ec7u \u0111i\u1ec7n th\u1ebf kh\u00e1c nhau.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2739},{"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":"D\u1ef1a v\u00e0o c\u00f4ng th\u1ee9c $R=\\dfrac{U}{I}$ c\u00f3 h\u1ecdc sinh ph\u00e1t bi\u1ec3u nh\u01b0 sau: \u201c\u0110i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y d\u1eabn t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u d\u00e2y v\u00e0 t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y\u201d. Ph\u00e1t bi\u1ec3u n\u00e0y \u0111\u00fang hay sai? V\u00ec sao?","select":["A. Sai. V\u00ec \u0111i\u1ec7n tr\u1edf ph\u1ee5 thu\u1ed9c v\u00e0o b\u1ea3n ch\u1ea5t v\u1eadt d\u1eabn, kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0 hi\u1ec7u \u0111i\u1ec7n th\u1ebf.","B. \u0110\u00fang. V\u00ec theo \u0111\u1ecbnh lu\u1eadt \u00d4m.","C. Sai. V\u00ec \u0111i\u1ec7n tr\u1edf ch\u1ec9 t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa hai \u0111\u1ea7u d\u00e2y d\u1eabn.","D. Sai. V\u00ec \u0111i\u1ec7n tr\u1edf ch\u1ec9 t\u1ec9 l\u1ec7 ngh\u1ecbch v\u1edbi c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y."],"hint":"","explain":"<span class='basic_left'>V\u00ec \u0111i\u1ec7n tr\u1edf ph\u1ee5 thu\u1ed9c v\u00e0o b\u1ea3n ch\u1ea5t v\u1eadt d\u1eabn, kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0 hi\u1ec7u \u0111i\u1ec7n th\u1ebf. C\u00f4ng th\u1ee9c tr\u00ean ch\u1ec9 bi\u1ec3u th\u1ecb m\u1ed1i quan h\u1ec7 U v\u00e0 I l\u00e0 t\u1ef7 l\u1ec7 thu\u1eadn v\u1edbi nhau. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":1}]}],"id_ques":2740},{"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":"\u0110\u1eb7t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 6V v\u00e0o hai \u0111\u1ea7u m\u1ed9t \u0111i\u1ec7n tr\u1edf th\u00ec d\u00f2ng \u0111i\u1ec7n \u0111i qua \u0111i\u1ec7n tr\u1edf c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 0,15A. N\u1ebfu t\u0103ng hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u \u0111i\u1ec7n tr\u1edf n\u00e0y l\u00ean th\u00e0nh 8V th\u00ec tr\u1ecb s\u1ed1 c\u1ee7a \u0111i\u1ec7n tr\u1edf n\u00e0y c\u00f3 thay \u0111\u1ed5i kh\u00f4ng? Tr\u1ecb s\u1ed1 c\u1ee7a n\u00f3 khi \u0111\u00f3 l\u00e0 bao nhi\u00eau? D\u00f2ng \u0111i\u1ec7n \u0111i qua n\u00f3 khi c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 l\u00e0 bao nhi\u00eau?","select":["A. R=10\u03a9 ; I=0,05A.","B. R=20\u03a9 ; I=0,1A.","C. R=30\u03a9 ; I=0,15A.","D. R=40\u03a9 ; I=0,2A."],"hint":"","explain":"<span class='basic_left'>N\u1ebfu t\u0103ng hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u \u0111i\u1ec7n tr\u1edf l\u00ean 8V th\u00ec \u0111i\u1ec7n tr\u1edf l\u00fac n\u00e0y v\u1eabn kh\u00f4ng thay \u0111\u1ed5i:<br\/>$R'=R=\\dfrac{U}{I}=\\dfrac{6}{0,15}=40\\Omega $<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua:<br\/>$I'=\\dfrac{U'}{R'}=\\dfrac{8}{40}=0,2A$ <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2741},{"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":"Gi\u1eefa hai \u0111\u1ea7u m\u1ed9t \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$ = 20\u03a9 c\u00f3 m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u00e0 U = 3,2V. T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I_{1}^{{}}$ \u0111i qua \u0111i\u1ec7n tr\u1edf n\u00e0y khi \u0111\u00f3. Gi\u1eef nguy\u00ean hi\u1ec7u \u0111i\u1ec7n th\u1ebf U \u0111\u00e3 cho tr\u00ean \u0111\u00e2y, thay \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$ b\u1eb1ng \u0111i\u1ec7n tr\u1edf $R_{2}^{{}}$ sao cho d\u00f2ng \u0111i\u1ec7n \u0111i qua $R_{2}^{{}}$ c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 $I_{2}^{{}}$ = 0,8 $I_{1}^{{}}$. T\u00ednh $R_{2}^{{}}$.","select":["A. $R_{2}^{{}}$=15\u03a9 ; $I_{1}^{{}}$=0,06A.","B. $R_{2}^{{}}$=20\u03a9 ; $I_{1}^{{}}$=0,12A.","C. $R_{2}^{{}}$=25\u03a9 ; $I_{1}^{{}}$=0,16A.","D. $R_{2}^{{}}$=30\u03a9 ; $I_{1}^{{}}$=0,2A."],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua \u0111i\u1ec7n tr\u1edf:<br\/>$I_{1}^{{}}=\\dfrac{U}{R_{1}^{{}}}=\\dfrac{3,2}{20}=0,16A$<br\/>Ta c\u00f3: $I_{2}^{{}}=0,8I_{1}^{{}}=0,8\\times 0,16=0,128A$<br\/>$\\Rightarrow $\u0110i\u1ec7n tr\u1edf qua $R_{2}^{{}}=\\dfrac{U}{I_{2}^{{}}}=\\dfrac{3,2}{0,128}=25\\Omega $.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2742},{"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/bai2/lv2/img\/h13.jpg'\/><\/center>Tr\u00ean h\u00ecnh 2.3 c\u00f3 v\u1ebd \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ed1i v\u1edbi hai \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$ v\u00e0 $R_{2}^{{}}$. T\u1eeb \u0111\u1ed3 th\u1ecb n\u00e0y h\u00e3y t\u00ednh tr\u1ecb s\u1ed1 c\u00e1c \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$v\u00e0 $R_{2}^{{}}$ ","select":["A. $R_{1}^{{}}$=10\u03a9 ; $R_{2}^{{}}$=15\u03a9.","B. $R_{1}^{{}}$=20\u03a9 ; $R_{2}^{{}}$=5\u03a9.","C. $R_{1}^{{}}$=5\u03a9; $R_{2}^{{}}$=20\u03a9.","D. $R_{1}^{{}}$=40\u03a9 ; $R_{2}^{{}}$=10\u03a9."],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ed3 th\u1ecb ta c\u00f3 t\u1ea1i v\u1ecb tr\u00ed ${{U}_{1}}=4V$ ; ${{I}_{1}}=0,2A$ n\u00ean:<br\/>$R_{1}^{{}}=\\dfrac{U_{1}^{{}}}{I_{1}^{{}}}=\\dfrac{4}{0,2}=20\\Omega $<br\/>T\u1ea1i v\u1ecb tr\u00ed ${{U}_{2}}=4V$; ${{I}_{2}}=0,8A$n\u00ean:<br\/>$R_{2}^{{}}=\\dfrac{U_{2}^{{}}}{R_{2}^{{}}}=\\dfrac{4}{0,8}=5\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2743},{"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":"T\u1eeb k\u1ebft qu\u1ea3 c\u1ee7a hai \u0111i\u1ec7n tr\u1edf t\u00ednh \u0111\u01b0\u1ee3c t\u1eeb b\u00e0i tr\u00ean. T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n $I_{1}^{{}}$, $I_{2}^{{}}$ t\u01b0\u01a1ng \u1ee9ng \u0111i qua m\u1ed7i \u0111i\u1ec7n tr\u1edf khi l\u1ea7n l\u01b0\u1ee3t \u0111\u1eb7t hi\u1ec7u \u0111i\u1ec7n th\u1ebf U=1,8V v\u00e0o hai \u0111\u1ea7u \u0111i\u1ec7n tr\u1edf \u0111\u00f3.","select":["A. $I_{1}^{{}}$=0,06A; $I_{2}^{{}}$ =0,24A.","B. $I_{1}^{{}}$=0,07A; $I_{2}^{{}}$ =0,28A.","C. $I_{1}^{{}}$=0,08A; $I_{2}^{{}}$ =0,32A.","D. $I_{1}^{{}}$=0,09A; $I_{2}^{{}}$ =0,36A."],"hint":"","explain":"<span class='basic_left'>\u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c \u0111\u1ecbnh lu\u1eadt \u00d4m ta c\u00f3:<br\/> $I_{1}^{{}}=\\dfrac{U}{R_{1}^{{}}}=\\dfrac{1,8}{20}=0,09A;$<br\/>$I_{2}^{{}}=\\dfrac{U}{R_{2}^{{}}}=\\dfrac{1,8}{5}=0,36A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2744},{"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/bai2/lv2/img\/h15.jpg'\/><\/center>Tr\u00ean h\u00ecnh v\u1ebd l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ed1i v\u1edbi 1 d\u00e2y d\u1eabn kh\u00e1c nhau. D\u1ef1a v\u00e0o \u0111\u1ed3 th\u1ecb cho bi\u1ebft \u0111i\u1ec7n tr\u1edf $R_{1}^{{}}$, $R_{2}^{{}}$, $R_{3}^{{}}$ c\u00f3 gi\u00e1 tr\u1ecb l\u00e0:","select":["A. $R_{1}^{{}}$ = 20\u03a9, $R_{2}^{{}}$ = 120\u03a9, $R_{3}^{{}}$ = 60\u03a9","B. $R_{1}^{{}}$ = 12\u03a9, $R_{2}^{{}}$ = 8,3\u03a9, $R_{3}^{{}}$ = 4,16\u03a9","C. $R_{1}^{{}}$ = 60\u03a9, $R_{2}^{{}}$ = 120\u03a9, $R_{3}^{{}}$ = 240\u03a9","D. $R_{1}^{{}}$ = 30\u03a9, $R_{2}^{{}}$ = 120\u03a9, $R_{3}^{{}}$ = 60\u03a9"],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ecbnh lu\u1eadt \u00d4m ta c\u00f3: $R=\\dfrac{U}{I}$<br\/>T\u1eeb \u0111\u1ed3 th\u1ecb \u1ee9ng v\u1edbi U=12V ta c\u00f3 c\u00e1c gi\u00e1 tr\u1ecb I ta suy ra:<br\/>$R_{1}^{{}}=\\dfrac{12}{0,2}=60\\Omega $; $R_{2}^{{}}=\\dfrac{12}{0,1}=120\\Omega $; $R_{3}^{{}}=\\dfrac{12}{0,05}=240\\Omega $.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2745},{"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: $U=I\\times R=300\\times {{10}^{-3}}\\times 50=15V$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2746},{"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/bai2/lv2/img\/h17.jpg'\/><\/center>Tr\u00ean h\u00ecnh v\u1ebd l\u00e0 \u0111\u1ed3 th\u1ecb bi\u1ec3u di\u1ec5n s\u1ef1 ph\u1ee5 thu\u1ed9c c\u1ee7a c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n v\u00e0 hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ed1i v\u1edbi hai d\u00e2y d\u1eabn kh\u00e1c nhau. D\u1ef1a v\u00e0o \u0111\u1ed3 th\u1ecb cho bi\u1ebft \u0111i\u1ec7n tr\u1edf ${{R}_{1}}$, $R_{2}^{{}}$, $R_{3}^{{}}$ c\u00f3 gi\u00e1 tr\u1ecb l\u00e0:","select":["A. $R_{1}^{{}}$ = 16\u03a9; $R_{2}^{{}}$ = 8\u03a9; $R_{3}^{{}}$ = 4\u03a9","B. $R_{1}^{{}}$= 12\u03a9; $R_{2}^{{}}$ = 8,3\u03a9; $R_{3}^{{}}$ = 4,16\u03a9","C. $R_{1}^{{}}$ = 60\u03a9; $R_{2}^{{}}$ = 120\u03a9; $R_{3}^{{}}$ = 240\u03a9","D. $R_{1}^{{}}$ = 62,5\u03a9; $R_{2}^{{}}$ = 125\u03a9; $R_{3}^{{}}$ = 250\u03a9"],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ecbnh lu\u1eadt \u00d4m ta c\u00f3: $R=\\dfrac{U}{I}$<br\/>T\u1eeb \u0111\u1ed3 th\u1ecb v\u1edbi U=10V v\u00e0 c\u00e1c gi\u00e1 tr\u1ecb I ta suy ra:<br\/>$R_{1}^{{}}=\\dfrac{10}{0,16}=62,5\\Omega $; $R_{2}^{{}}=\\dfrac{10}{0,08}=125\\Omega $; $R_{3}^{{}}=\\dfrac{10}{0,04}=250\\Omega $.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2747},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"M\u1ed9t d\u00e2y d\u1eabn \u0111\u01b0\u1ee3c m\u1eafc v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 15V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 l\u00e0 0,5A. N\u1ebfu gi\u1ea3m hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o hai \u0111\u1ea7u d\u00e2y d\u1eabn \u0111i 3V th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y d\u1eabn khi c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n:","select":["A. I\u2019 = 0,2A.","B. I\u2019 = 0,3A.","C. I\u2019 = 0,4A.","D. I\u2019 = 0,5A."],"hint":"","explain":"<span class='basic_left'>T\u1eeb \u0111\u1ecbnh lu\u1eadt \u00d4m ta c\u00f3 \u0111i\u1ec7n tr\u1edf b\u00f3ng \u0111\u00e8n: <br\/>$R=\\dfrac{U}{I}=\\dfrac{15}{0,5}=30\\Omega $ <br\/>Khi gi\u1ea3m hi\u1ec7u \u0111i\u1ec7n th\u1ebf:<br\/>$\\Delta U=4V\\Rightarrow U'=15-3=12V$<br\/>V\u1eady c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n:<br\/>$I'=\\dfrac{U'}{R}=\\dfrac{12}{30}=0,4A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2748},{"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":"<center><img src='https://www.luyenthi123.com/file/luyenthi123/lop9/vatly/bai2/lv2/img\/h19.jpg'\/><\/center>M\u1ed9t d\u00e2y d\u1eabn \u0111\u01b0\u1ee3c m\u1eafc v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 8V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 l\u00e0 0,4A. Quan s\u00e1t b\u1ea3ng gi\u00e1 tr\u1ecb hi\u1ec7u \u0111i\u1ec7n th\u1ebf v\u00e0 c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n sau \u0111\u00e2y v\u00e0 cho bi\u1ebft gi\u00e1 tr\u1ecb n\u00e0o c\u1ee7a A, B, C, D l\u00e0 kh\u00f4ng ph\u00f9 h\u1ee3p?","select":["A. 0,54A.","B. 0,8A.","C. 19V.","D. 20V."],"hint":"","explain":"<span class='basic_left'>$R=\\dfrac{U}{I}=\\dfrac{8}{0,4}=20\\Omega $<br\/>V\u1eady U=9V th\u00ec $I=\\dfrac{9}{20}=0,45A$ \u1edf \u0111\u00e2y l\u00e0 0,54A n\u00ean kh\u00f4ng ph\u00f9 h\u1ee3p. <br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2749},{"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 d\u1ea7u d\u00e2y d\u1eabn m\u1ed9t hi\u1ec7u \u0111i\u1ec7n th\u1ebf 120V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 l\u00e0 5A. N\u1ebfu hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t v\u00e0o \u0111i\u1ec7n tr\u1edf \u0111\u00f3 l\u00e0 360V th\u00ec c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y trong d\u00e2y d\u1eabn l\u00e0 bao nhi\u00eau?","select":["A. I = 10A","B. I = 15A","C. I = 2A ","D. I = 25A"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf d\u00e2y d\u1eabn: $R=\\dfrac{U}{I}=\\dfrac{120}{5}=24\\Omega $<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n: $I=\\dfrac{360}{24}=15A$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2750}],"lesson":{"save":0,"level":2}}