本题目来源于试卷: Electric Field and Electric Induction，类别为 美国物理杯赛(Physics Bowl)
[单选题]
02.24: Two small holl vk-ganz+c 5k. o fr ),j-sdle7 *jrveq/s. :wwk w metal spheres hung on insulating threads attract one another as shown. It is known that a positively charg ejjf7e kr.*wr l,/d: )qs-wvsed rod will attract ball A.
I. Ball A has a positive charge
II. Ball B has a negative charge
III. Ball A and Ball B have opposite charges
Which of the above can be correctly concluded about the charge on the balls?
A. I only
B. II only
C. III only
D. all of these
E. none of these
参考答案: E
本题详细解析:
暂无
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