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{"segment":[{"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\u1ec7n n\u0103ng kh\u00f4ng th\u1ec3 bi\u1ebfn \u0111\u1ed5i th\u00e0nh:","select":["A. C\u01a1 n\u0103ng","B. Nhi\u1ec7t n\u0103ng","C. H\u00f3a n\u0103ng","D. N\u0103ng l\u01b0\u1ee3ng nguy\u00ean t\u1eed"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n n\u0103ng kh\u00f4ng th\u1ec3 bi\u1ebfn \u0111\u1ed5i th\u00e0nh n\u0103ng l\u01b0\u1ee3ng nguy\u00ean t\u1eed.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2951},{"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 su\u1ea5t \u0111i\u1ec7n cho bi\u1ebft:","select":["A. kh\u1ea3 n\u0103ng th\u1ef1c hi\u1ec7n c\u00f4ng c\u1ee7a d\u00f2ng \u0111i\u1ec7n","B. n\u0103ng l\u01b0\u1ee3ng c\u1ee7a d\u00f2ng \u0111i\u1ec7n","C. l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng s\u1eed d\u1ee5ng trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian","D. m\u1ee9c \u0111\u1ed9 m\u1ea1nh, y\u1ebfu c\u1ee7a d\u00f2ng \u0111i\u1ec7n"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t \u0111i\u1ec7n cho bi\u1ebft l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng s\u1eed d\u1ee5ng trong m\u1ed9t \u0111\u01a1n v\u1ecb th\u1eddi gian.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2952},{"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":"Tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi 220V \u2013 100W. T\u00ednh \u0111i\u1ec7n n\u0103ng s\u1eed d\u1ee5ng trong 30 ng\u00e0y khi th\u1eafp s\u00e1ng b\u00ecnh th\u01b0\u1eddng b\u00f3ng \u0111\u00e8n m\u1ed7i ng\u00e0y 4 gi\u1edd","select":["A. 4kWh","B. 8kWh","C. 12kWh","D. 16kWh"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n n\u0103ng s\u1eed d\u1ee5ng trong 30 ng\u00e0y l\u00e0: $A=0,140=12kWh$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2953},{"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":"Tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi 220V \u2013 100W. M\u1eafc n\u1ed1i ti\u1ebfp hai b\u00f3ng \u0111\u00e8n c\u00f9ng lo\u1ea1i tr\u00ean \u0111\u00e2y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V. T\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a \u0111o\u1ea1n m\u1ea1ch n\u1ed1i ti\u1ebfp n\u00e0y v\u00e0 t\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a m\u1ed7i b\u00f3ng \u0111\u00e8n khi \u0111\u00f3.","select":["A. 5W","B. 25W","C. 50W","D. 125W"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n l\u00e0: <br\/>$R=\\dfrac{{{U}^{2}}}{P}=\\dfrac{{{220}^{2}}}{100}=484\\Omega $<br\/>Khi hai \u0111\u00e8n m\u1eafc n\u1ed1i ti\u1ebfp, c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ed7i \u0111\u00e8n l\u00e0:<br\/>$I=\\dfrac{U}{{{R}_{td}}}=\\dfrac{U}{2R}=\\dfrac{220}{2\\times 484}=0,227A$<br\/>C\u00f4ng su\u1ea5t c\u1ee7a \u0111o\u1ea1n m\u1ea1ch n\u1ed1i ti\u1ebfp l\u00e0: <br\/>${{P}_{dm}}=U\\times I=220\\times 0,227\\approx 50W$.<br\/>C\u00f4ng su\u1ea5t c\u1ee7a m\u1ed7i b\u00f3ng \u0111\u00e8n l\u00e0: <br\/>$P=\\dfrac{{{P}_{dm}}}{2}=\\dfrac{50}{2}=25W$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2954},{"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":"Tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi 220V \u2013 100W. M\u1eafc n\u1ed1i ti\u1ebfp b\u00f3ng \u0111\u00e8n n\u00e0y v\u1edbi m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c kh\u00e1c c\u00f3 ghi 220V \u2013 75W v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V. H\u00e3y t\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a \u0111o\u1ea1n m\u1ea1ch n\u00e0y.","select":["A. 29,4W","B. 42,9W","C. 24,9W","D. 49,2W"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 nh\u1ea5t l\u00e0: ${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{220}^{2}}}{100}=484\\Omega $<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 hai l\u00e0: ${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{220}^{2}}}{75}=645,5\\Omega $<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua hai \u0111\u00e8n l\u00e0: $I=\\dfrac{U}{R}=0,195A$<br\/>V\u00ec ${{R}_{1}}$ v\u00e0 ${{R}_{2}}$ m\u1eafc n\u1ed1i ti\u1ebfp n\u00ean: ${{I}_{1}}={{I}_{2}}=I=0,195A$.<br\/>Hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t l\u00ean m\u1ed7i \u0111\u00e8n l\u00e0:<br\/> ${{U}_{1}}=\\text{I}\\times {{\\text{R}}_{1}}=94,4V$ <br\/>${{U}_{2}}=\\text{I}\\times {{\\text{R}}_{2}}=125,8V$<br\/>V\u00ec ${{U}_{1}}$ v\u00e0 ${{U}_{2}}$ \u0111\u1ec1u nh\u1ecf h\u01a1n hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ecbnh m\u1ee9c n\u00ean c\u00e1c \u0111\u00e8n kh\u00f4ng b\u1ecb h\u1ecfng. C\u00f4ng su\u1ea5t c\u1ee7a \u0111o\u1ea1n m\u1ea1ch l\u00e0: ${{P}_{dm}}=U\\times I=220\\times 0,195=42,9W$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2955},{"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":"Tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n t\u00f3c \u0111\u1ecf c\u00f3 ghi 220V \u2013 100W v\u00e0 tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n kh\u00e1c c\u00f3 ghi 220V \u2013 40W. Cho bi\u1ebft t\u1ec9 s\u1ed1 $\\dfrac{{{R}_{2}}}{{{R}_{1}}}$khi ch\u00fang s\u00e1ng b\u00ecnh th\u01b0\u1eddng.","select":["A. 1","B. 2,5","C. 3","D. 4"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 nh\u1ea5t l\u00e0: ${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{220}^{2}}}{100}=484\\Omega $<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 hai l\u00e0: ${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{220}^{2}}}{40}=1210\\Omega $<br\/>L\u1eadp t\u1ec9 l\u1ec7: $\\dfrac{{{R}_{2}}}{{{R}_{1}}}=\\dfrac{1210}{484}=2,5$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2956},{"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 m\u1ed9t b\u00f3ng \u0111\u00e8n t\u00f3c \u0111\u1ecf c\u00f3 ghi 220V \u2013 100W v\u00e0 tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n kh\u00e1c c\u00f3 ghi 220V \u2013 40W. M\u1eafc n\u1ed1i ti\u1ebfp hai b\u00f3ng \u0111\u00e8n n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V. T\u00ednh \u0111i\u1ec7n n\u0103ng m\u00e0 m\u1ea1ch \u0111i\u1ec7n n\u00e0y s\u1eed d\u1ee5ng trong 1 gi\u1edd. Cho r\u1eb1ng \u0111i\u1ec7n tr\u1edf c\u1ee7a c\u00e1c b\u00f3ng \u0111\u00e8n c\u00f3 gi\u00e1 tr\u1ecb nh\u01b0 khi ch\u00fang s\u00e1ng b\u00ecnh th\u01b0\u1eddng.","select":["A. 0,0286kWh","B. 0,0268kWh","C. 0,0572kWh","D. 0,0862kWh"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 nh\u1ea5t l\u00e0: ${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{220}^{2}}}{100}=484\\Omega $<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a \u0111\u00e8n th\u1ee9 hai l\u00e0: ${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{220}^{2}}}{40}=1210\\Omega $<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n trong \u0111o\u1ea1n m\u1ea1ch l\u00e0:$I=\\dfrac{U}{R}=\\dfrac{U}{{{R}_{1}}+{{R}_{2}}}=\\dfrac{220}{484+1210}=0,13A$ <br\/>\u0110i\u1ec7n n\u0103ng ti\u00eau th\u1ee5 c\u1ee7a \u0111o\u1ea1n m\u1ea1ch trong 1 gi\u1edd l\u00e0: $A=U\\times I\\times t=220\\times 0,13\\times 3600=102960J=0,0286kWh$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2957},{"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":"Tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n t\u00f3c \u0111\u1ecf c\u00f3 ghi 220V \u2013 100W v\u00e0 tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n kh\u00e1c c\u00f3 ghi 220V \u2013 40W. M\u1eafc song song hai b\u00f3ng \u0111\u00e8n n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V. T\u00ednh \u0111i\u1ec7n n\u0103ng m\u00e0 \u0111\u00e8n n\u00e0y s\u1eed d\u1ee5ng trong 1 gi\u1edd.","select":["A. 0,7kWh","B. 0,14kWh","C. 0,28kWh","D. 0,21kWh"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n n\u0103ng m\u1ea1ch \u0111i\u1ec7n ti\u00eau th\u1ee5 trong 1 gi\u1edd l\u00e0:<br\/>$A=\\left( {{P}_{1}}+{{P}_{2}} \\right)\\times t=\\left( 100+40 \\right)\\times 3600=504000J=0,14kWh$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2958},{"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":"Tr\u00ean m\u1ed9t b\u00e0n l\u00e0 c\u00f3 ghi 110V \u2013 550W v\u00e0 tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi 110V \u2013 40W. T\u00ednh \u0111i\u1ec7n tr\u1edf c\u1ee7a b\u00e0n l\u00e0 v\u00e0 b\u00f3ng \u0111\u00e8n khi ch\u00fang ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng.","select":["A. 11\u03a9; 203,5\u03a9","B. 22\u03a9; 302,5\u03a9","C. 22\u03a9; 230,5\u03a9","D. 11\u03a9; 302,5\u03a9"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a b\u00e0n l\u00e0 l\u00e0: ${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{110}^{2}}}{550}=22\\Omega $ \u0110i\u1ec7n tr\u1edf c\u1ee7a b\u00f3ng \u0111\u00e8n l\u00e0: ${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{110}^{2}}}{40}=302,5\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2959},{"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":"Tr\u00ean m\u1ed9t b\u00e0n l\u00e0 c\u00f3 ghi 110V \u2013 550W v\u00e0 tr\u00ean m\u1ed9t b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi 110V \u2013 40W. C\u00f3 th\u1ec3 m\u1eafc n\u1ed1i ti\u1ebfp hai d\u1ee5ng c\u1ee5 n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t l\u00e0 bao nhi\u00eau \u0111\u1ec3 ch\u00fang kh\u00f4ng b\u1ecb h\u1ecfng? ","select":["A. 220V","B. 110V","C. 1622V","D. 118V"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a b\u00e0n l\u00e0 l\u00e0: ${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{110}^{2}}}{550}=22\\Omega $<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a b\u00f3ng \u0111\u00e8n l\u00e0: ${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{110}^{2}}}{40}=302,5\\Omega $<br\/>C\u01b0\u1eddng \u0111\u1ed9 \u0111\u1ecbnh m\u1ee9c c\u1ee7a b\u00e0n l\u00e0 v\u00e0 \u0111\u00e8n t\u01b0\u01a1ng \u1ee9ng l\u00e0:<br\/> ${{I}_{1}}=\\dfrac{{{P}_{1}}}{{{U}_{1}}}=\\dfrac{550}{110}=5A$<br\/>${{I}_{2}}=\\dfrac{{{P}_{2}}}{{{U}_{2}}}=\\dfrac{40}{110}=0,364A$. <br\/>Khi m\u1eafc n\u1ed1i ti\u1ebfp hai d\u1ee5ng c\u1ee5 \u0111i\u1ec7n n\u00e0y th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua ch\u00fang c\u00f3 c\u00f9ng c\u01b0\u1eddng \u0111\u1ed9 v\u00e0 ch\u1ec9 c\u00f3 th\u1ec3 l\u1edbn nh\u1ea5t l\u00e0 ${{I}_{\\max }}={{I}_{2}}=0,364A$, v\u00ec n\u1ebfu l\u1edbn h\u01a1n th\u00ec b\u00f3ng \u0111\u00e8n s\u1ec5 h\u1ecfng. V\u1eady c\u00f3 th\u1ec3 m\u1eafc n\u1ed1i ti\u1ebfp hai d\u1ee5ng c\u1ee5 n\u00e0y v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf l\u1edbn nh\u1ea5t l\u00e0:<br\/>${{U}_{\\max }}={{I}_{\\max }}\\times \\left( {{R}_{1}}+{{R}_{2}} \\right)=118V$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2960},{"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 qu\u1ea1t \u0111i\u1ec7n d\u00f9ng tr\u00ean xe \u00f4 t\u00f4 c\u00f3 ghi 12V \u2013 15W. C\u1ea7n ph\u1ea3i m\u1eafc qu\u1ea1t v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf bao nhi\u00eau \u0111\u1ec3 cho n\u00f3 ch\u1ea1y b\u00ecnh th\u01b0\u1eddng? T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua khi \u0111\u00f3.","select":["A. 0,25A","B. 0,75A","C. 1A","D. 1,25A"],"hint":"","explain":"<span class='basic_left'>Ph\u1ea3i m\u1eafc qu\u1ea1t v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ecbnh m\u1ee9c U = 12V.<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a qu\u1ea1t l\u00e0: $R=\\dfrac{{{U}^{2}}}{P}=\\dfrac{{{12}^{2}}}{15}=9,6\\Omega $.<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua qu\u1ea1t l\u00e0: $I=\\dfrac{U}{R}=\\dfrac{12}{9,6}=1,25A$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2961},{"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 qu\u1ea1t \u0111i\u1ec7n d\u00f9ng tr\u00ean xe \u00f4 t\u00f4 c\u00f3 ghi 12V \u2013 15W. T\u00ednh \u0111i\u1ec7n n\u0103ng m\u00e0 qu\u1ea1t s\u1eed d\u1ee5ng trong m\u1ed9t gi\u1edd khi ch\u1ea1y b\u00ecnh th\u01b0\u1eddng.","select":["A. 0,005kWh","B. 0,01kWh","C. 0,015kWh","D. 0,02kWh"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a qu\u1ea1t l\u00e0: $R=\\dfrac{{{U}^{2}}}{P}=\\dfrac{{{12}^{2}}}{15}=9,6\\Omega $.<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua qu\u1ea1t l\u00e0: $I=\\dfrac{U}{R}=\\dfrac{12}{9,6}=1,25A$.<br\/>\u0110i\u1ec7n n\u0103ng qu\u1ea1t ti\u00eau th\u1ee5 trong 1 gi\u1edd l\u00e0:<br\/>$A=U\\times I\\times t=12\\times 1,25\\times 3600=54000J=0,015kWh$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2962},{"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 qu\u1ea1t \u0111i\u1ec7n d\u00f9ng tr\u00ean xe \u00f4 t\u00f4 c\u00f3 ghi 12V \u2013 15W. Khi qu\u1ea1t ch\u1ea1y , \u0111i\u1ec7n n\u0103ng \u0111\u01b0\u1ee3c bi\u1ebfn \u0111\u1ed5i th\u00e0nh c\u00e1c d\u1ea1ng n\u0103ng l\u01b0\u1ee3ng n\u00e0o? Cho r\u1eb1ng hi\u1ec7u su\u1ea5t c\u1ee7a qu\u1ea1t l\u00e0 85%, t\u00ednh \u0111i\u1ec7n tr\u1edf c\u1ee7a qu\u1ea1t.","select":["A. 0,44\u03a9","B. 1,44\u03a9","C. 1,14\u03a9","D. 4,11\u03a9"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a qu\u1ea1t l\u00e0: $R=\\dfrac{{{U}^{2}}}{P}=\\dfrac{{{12}^{2}}}{15}=9,6\\Omega $.<br\/>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua qu\u1ea1t l\u00e0: $I=\\dfrac{U}{R}=\\dfrac{12}{9,6}=1,25A$.<br\/>\u0110i\u1ec7n n\u0103ng \u0111\u01b0\u1ee3c bi\u1ebfn \u0111\u1ed5i th\u00e0nh c\u01a1 n\u0103ng v\u00e0 nhi\u1ec7t n\u0103ng.<br\/>Ph\u1ea7n \u0111i\u1ec7n n\u0103ng bi\u1ebfn \u0111\u1ed5i th\u00e0nh nhi\u1ec7t n\u0103ng trong 1 gi\u00e2y l\u00e0: <br\/>${{P}_{nh}}=P\\times \\left( 1-H \\right)=15\\times 0,15=2,25J$<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a qu\u1ea1t l\u00e0: $R=\\dfrac{{{P}_{nh}}}{{{I}^{2}}}=1,44\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2963},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[2]],"list":[{"point":5,"ques":"M\u1ed9t b\u00e0n l\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V th\u00ec ti\u00eau th\u1ee5 v\u1edbi m\u1ed9t l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng l\u00e0 990kJ trong 15 ph\u00fat. T\u00ednh c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y nung c\u1ee7a b\u00e0n l\u00e0 khi \u0111\u00f3.","select":["A. 5,45A","B. 5A","C. 2,5A","D. 1,25A"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua d\u00e2y nung:<br\/>$A=U\\times I\\times t\\Rightarrow I=\\dfrac{A}{U\\times t}=\\dfrac{990000}{220\\times 15\\times 60}=5A$.<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 B.<\/span><\/span> ","column":2}]}],"id_ques":2964},{"time":24,"part":[{"title":"L\u1ef1a ch\u1ecdn \u0111\u00e1p \u00e1n \u0111\u00fang nh\u1ea5t","title_trans":"","temp":"multiple_choice","correct":[[3]],"list":[{"point":5,"ques":"M\u1ed9t b\u00e0n l\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V th\u00ec ti\u00eau th\u1ee5 v\u1edbi m\u1ed9t l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng l\u00e0 880kJ trong 10 ph\u00fat. T\u00ednh \u0111i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y nung n\u00e0y khi \u0111\u00f3.","select":["A. 11\u03a9","B. 44\u03a9","C. 33\u03a9","D. 22\u03a9"],"hint":"","explain":"<span class='basic_left'>C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n qua d\u00e2y nung:<br\/>$A=U\\times I\\times t\\Rightarrow I=\\dfrac{A}{U\\times t}=\\dfrac{880000}{220\\times 10\\times 60}=6,67A$.<br\/>\u0110i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y nung: $R=\\dfrac{U}{I}=\\dfrac{220}{6,67}\\approx 33\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2965},{"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":"M\u1ed9t b\u1ebfp \u0111i\u1ec7n \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y nung c\u1ee7a b\u1ebfn c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 I = 6,8A. T\u00ednh c\u00f4ng su\u1ea5t c\u1ee7a b\u1ebfp \u0111i\u1ec7n khi \u0111\u00f3.","select":["A. 1496W","B. 1649W","C. 1946W","D. 1469W"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t ti\u00eau th\u1ee5 c\u1ee7a b\u1ebfp: $P=U\\times I=220\\times 6,8=1496W$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2966},{"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 bi\u1ebfp \u0111i\u1ec7n \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi hi\u1ec7u \u0111i\u1ec7n th\u1ebf 220V th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u00e2y nung c\u1ee7a b\u1ebfn c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 I = 6,8A. M\u1ed7i ng\u00e0y b\u1ebfp \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng nh\u01b0 tr\u00ean trong 45 ph\u00fat. T\u00ednh ph\u1ea7n \u0111i\u1ec7n n\u0103ng c\u00f3 \u00edch m\u00e0 b\u1ebfp cung c\u1ea5p trong 30 ng\u00e0y, bi\u1ebft r\u1eb1ng hi\u1ec7u su\u1ea5t c\u1ee7a b\u1ebfp l\u00e0 H = 80%","select":["A. 28,269kWh","B. 19,268kWh","C. 22,457kWh","D. 26,928kWh"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t ti\u00eau th\u1ee5 c\u1ee7a b\u1ebfp: $P=U\\times I=220\\times 6,8=1496W$\u0110i\u1ec7n n\u0103ng ti\u00eau th\u1ee5 c\u1ee7a b\u1ebfp trong 30 ng\u00e0y.<br\/>$A=P\\times t=1496\\times 30\\times 45\\times 60=121176000J$<br\/>\u0110i\u1ec7n n\u0103ng c\u00f3 \u00edch c\u1ee7a b\u1ebfp:<br\/>${{A}_{i}}=\\dfrac{A\\times H}{100}=\\dfrac{121176000\\times 80}{100}=96940800J=26,928kWh$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2967},{"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":"Cho hai b\u00f3ng \u0111\u00e8n d\u00e2y t\u00f3c c\u00f3 ghi s\u1ed1 6V \u2013 2W v\u00e0 6V \u2013 3W. T\u00ednh \u0111i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y t\u00f3c m\u1ed7i b\u00f3ng \u0111\u00e8n n\u00e0y khi ch\u00fang s\u00e1ng b\u00ecnh th\u01b0\u1eddng.","select":["A. 6\u03a9; 18\u03a9","B. 12\u03a9; 9\u03a9","C. 6\u03a9; 9\u03a9","D. 12\u03a9; 18\u03a9"],"hint":"","explain":"<span class='basic_left'>\u0110i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y t\u00f3c b\u00f3ng \u0111\u00e8n $\u0110_1$ v\u00e0 $\u0110_2$: <br\/>${{R}_{1}}=\\dfrac{{{U}_{1}}^{2}}{{{P}_{1}}}=\\dfrac{{{6}^{2}}}{3}=12\\Omega $<br\/>${{R}_{2}}=\\dfrac{{{U}_{2}}^{2}}{{{P}_{2}}}=\\dfrac{{{6}^{2}}}{2}=18\\Omega $<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 D.<\/span><\/span> ","column":2}]}],"id_ques":2968},{"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 \u0111o\u1ea1n m\u1ea1ch c\u00f3 \u0111i\u1ec7n tr\u1edf R \u0111\u01b0\u1ee3c m\u1eafc v\u00e0o hi\u1ec7u \u0111i\u1ec7n th\u1ebf U th\u00ec d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua n\u00f3 c\u00f3 c\u01b0\u1eddng \u0111\u1ed9 I v\u00e0 c\u00f4ng su\u1ea5t \u0111i\u1ec7n c\u1ee7a n\u00f3 l\u00e0 P. \u0110i\u1ec7n n\u0103ng m\u00e0 \u0111o\u1ea1n m\u1ea1ch n\u00e0y ti\u00eau th\u1ee5 trong th\u1eddi gian t l\u00e0:","select":["A. $A=R\\times I\\times t$","B. $A=\\dfrac{P\\times t}{R}$","C. $A=U\\times I\\times t$","D. $A=\\dfrac{{{P}^{2}}}{R}$"],"hint":"","explain":"<span class='basic_left'><br\/> <span class='basic_pink'>\u0110i\u1ec7n n\u0103ng ti\u00eau th\u1ee5 c\u1ee7a \u0111o\u1ea1n m\u1ea1ch ch\u00ednh l\u00e0 n\u0103ng l\u01b0\u1ee3ng \u0111i\u1ec7n \u0111\u01b0\u1ee3c chuy\u1ec3n h\u00f3a th\u00e0nh c\u00f4ng \u0111\u1ec3 c\u00f3 th\u1ec3 d\u1ecbch chuy\u1ec3n c\u00e1c \u0111i\u1ec7n t\u00edch \u1edf trong m\u1ea1ch. A=P.t=U.I.t\u200b. V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 C.<\/span><\/span> ","column":2}]}],"id_ques":2969},{"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":"M\u1ed9t b\u00e0n l\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng v\u1edbi \u0111\u00fang hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1ecbnh m\u1ee9c, trong 15 ph\u00fat th\u00ec ti\u00eau th\u1ee5 m\u1ed9t l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng 720KJ. C\u00f4ng su\u1ea5t c\u1ee7a b\u00e0n l\u00e0 l\u00e0 bao nhi\u00eau?","select":["A. P = 800W","B. P = 800kW","C. P = 800J","D. P = 800N"],"hint":"","explain":"<span class='basic_left'>C\u00f4ng su\u1ea5t c\u1ee7a b\u00e0n l\u00e0: $P=\\dfrac{A}{t}=\\dfrac{720000}{15\\times 60}=800W$<br\/> <span class='basic_pink'>V\u1eady \u0111\u00e1p \u00e1n \u0111\u00fang l\u00e0 A.<\/span><\/span> ","column":2}]}],"id_ques":2970}],"lesson":{"save":0,"level":2}}

Điểm của bạn.

Câu hỏi này theo dạng chọn đáp án đúng, sau khi đọc xong câu hỏi, bạn bấm vào một trong số các đáp án mà chương trình đưa ra bên dưới, sau đó bấm vào nút gửi để kiểm tra đáp án và sẵn sàng chuyển sang câu hỏi kế tiếp

Trả lời đúng trong khoảng thời gian quy định bạn sẽ được + số điểm như sau:
Trong khoảng 1 phút đầu tiên + 5 điểm
Trong khoảng 1 phút -> 2 phút + 4 điểm
Trong khoảng 2 phút -> 3 phút + 3 điểm
Trong khoảng 3 phút -> 4 phút + 2 điểm
Trong khoảng 4 phút -> 5 phút + 1 điểm

Quá 5 phút: không được cộng điểm

Tổng thời gian làm mỗi câu (không giới hạn)

Điểm của bạn.

Bấm vào đây nếu phát hiện có lỗi hoặc muốn gửi góp ý