Điện trở. Định luật Ohm

Home Lớp 9 Khoa học tự nhiên 9 - sách kết nối tri thức Bài 11: Điện trở. Định luật OhmBài tập nâng cao

{"common":{"save":0,"post_id":"8242","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9475","post_id":"8242","mon_id":"1159533","chapter_id":"1159663","question":"M\u1ed9t \u0111o\u1ea1n m\u1ea1ch có \u0111i\u1ec7n tr\u1edf R = 20 Ω, hi\u1ec7u \u0111i\u1ec7n th\u1ebf \u0111\u1eb7t vào hai \u0111\u1ea7u \u0111o\u1ea1n m\u1ea1ch là U = 40 V. C\u01b0\u1eddng \u0111\u1ed9 dòng \u0111i\u1ec7n qua m\u1ea1ch là bao nhiêu?<\/p>","options":["A. 1 A","B. 2 A","C. 0,5 A","D. 3 A"],"correct":"2","level":"3","hint":"","answer":"\u0110áp án: B. 2 A<\/p>Gi\u1ea3i thích:<\/p>Theo \u0111\u1ecbnh lu\u1eadt Ohm: $I = {U \\over R}= {40 \\over 20} = 2\\ A$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-31 12:37:57","option_type":"txt","len":0},{"id":"9476","post_id":"8242","mon_id":"1159533","chapter_id":"1159663","question":"M\u1ed9t dây d\u1eabn có chi\u1ec1u dài l = 2 m, ti\u1ebft di\u1ec7n $S = 2.10^{-6}\\ m^2$<\/span>, và \u0111i\u1ec7n tr\u1edf su\u1ea5t $\u03c1 = 1,7.10^{-8}\\ \u03a9m$<\/span>. \u0110i\u1ec7n tr\u1edf c\u1ee7a dây d\u1eabn là:<\/p>","options":["A. 17 Ω","B. 0,017 Ω","C. 0,34 Ω","D. 1,7 Ω"],"correct":"2","level":"3","hint":"","answer":"\u0110áp án: B. 0.017 Ω<\/p>Gi\u1ea3i thích:<\/p>Công th\u1ee9c tính \u0111i\u1ec7n tr\u1edf: $R = \u03c1.{l \\over S} $<\/span> = 0,017 Ω<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-31 12:42:07","option_type":"txt","len":2},{"id":"9477","post_id":"8242","mon_id":"1159533","chapter_id":"1159663","question":"M\u1ed9t \u0111o\u1ea1n m\u1ea1ch g\u1ed3m 2 \u0111i\u1ec7n tr\u1edf $R_1 = 4\\ \u03a9$<\/span> và $R_2 = 6\\ \u03a9$<\/span> m\u1eafc n\u1ed1i ti\u1ebfp. Hi\u1ec7u \u0111i\u1ec7n th\u1ebf gi\u1eefa 2 \u0111\u1ea7u \u0111o\u1ea1n m\u1ea1ch là U = 20 V. C\u01b0\u1eddng \u0111\u1ed9 dòng \u0111i\u1ec7n qua m\u1ea1ch là:<\/p>","options":["A. 0,5 A","B. 1 A","C. 2 A","D. 1,5 A"],"correct":"3","level":"3","hint":"","answer":"\u0110áp án: C. 2 A<\/p>Gi\u1ea3i thích:<\/p>- T\u1ed5ng \u0111i\u1ec7n tr\u1edf c\u1ee7a m\u1ea1ch: $R = R_1 + R_2 = 4 +6 = 10\\ \u03a9$<\/span><\/p>- Theo \u0111\u1ecbnh lu\u1eadt Ohm: $I = {U\\over R} = {20 \\over 10} = 2\\ A$<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"125","test":"0","date":"2024-12-31 12:54:25","option_type":"txt","len":0}]}