本题目来源于试卷: Fields D.3 Motion in Electromagnetic Fields，类别为 IB物理学
[单选题]
A current-carrying wirn r8bte,txo6t8.q f o(e ihj9 cml 3kjj28r )ohq1s at right angles to a uniform magnetic field. The magnetic force per unit8m2j 1hj)kq 9hcr o3lj length on the wire is $\frac{F}{L}$. The length of the wire, the magnitude of the magnetic field strength, and the current of the wire are all doubled. Which of the following is the magnetic force per unit length on the wire after these changes?
A. $\frac{F}{L}$
B. $\frac{2F}{L}$
C. $\frac{4F}{L}$
D. $\frac{8F}{L}$
参考答案: C
本题详细解析:
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