Một đoạn dây dẫn có dòng điện I nằm ngang đặt tron...
Câu hỏi: Một đoạn dây dẫn có dòng điện I nằm ngang đặt trong từ trường có đường sức từ thẳng đứng từ trên xuống như hình vẽ. Lực từ tác dụng lên đoạn dây dẫn có chiều![](data:image/png;base64,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)
A. thẳng đứng hướng từ dưới lên.
B. thẳng đứng hướng từ trên xuống dưới.
C. nằm ngang hướng từ trái sang phải.
D. nằm ngang hướng từ phải sang trái.
Câu hỏi trên thuộc đề trắc nghiệm
Đề thi thử THPT QG 2018 môn Vật lý- Sở GD&ĐT Thái Bình