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chienhien2014
2 năm trước
Người ta muốn truyền đi một công suất p bằng dây dẫn dài 20km, dây dẫn có điện trở 6 ôm. Hiệu điện thế giữa hai đầu dây của trạm truyền đi là 20kV, Công suất hao phí trên đường dây truyền tải điện là 375KW a) Tính hiệu suất của việc truyền tải điện năng này. b) Muốn giảm công suất hao phí đi 100 lần chỉ bằng cách thay đổi hiệu điện thế ở hai đầu dây của trạm truyền thì hiệu điện thế này bây giờ là bao nhiêu? giải giúp minh bài này với ạ
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