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Hân Ngos
2 năm trước

hai dây nhôm có cùng tiếp diện 1 dây dài l1 có điện trở l1, dây kia có chiều dài l2 và có điện trở l2 thì tỉ số r1:r2 bằng gì?

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quangdoan
2 năm trước

Đáp án:

 $\frac{R_1}{R_2}=\frac{l_1}{l_2}$ 

Giải thích các bước giải:

 $\frac{R_1}{R_2}=\frac{\frac{\rho l_1}{S}}{\frac{\rho l_2}{S}}=\frac{l_1}{l_2}$

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