本题目来源于试卷: Motion of charged particle and Velocity selector and Mass spectrometer，类别为 美国物理杯赛(Physics Bowl)
[单选题]
14.29 An electron with charge −e and mas dql1p7bjr8n 8s m travwamqk+ irkt+;; 5b7d nels at a speed v in a plane perpendicular to a magnetic field of magnitude B. The electron follows a circular path of radius R. In a time t, the electron travels halfway around the circle. What is the amount of work done by the magnk rid;m7nqba++wt 5;k etic force on the electron in this time?
A. 0
B. $-\pi$evBR
C. $\pi$evBR
D. -2evBR
E. $\frac{\pi\:mv}{eB}$
参考答案: A
本题详细解析:
暂无
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