[单选题]
The diagram shows the equipotential li
8 b8kiho ml58unes in a field due to A
lgrf,q; g zk:te,a 6o4and B. What may be represented by
f z tko4gqgr ,6a;:e,lA and B?
I. 2 equal masses.
II. 2 equal charges of the same sign.
III. 2 equal charges of opposite sign
A. Only $I$
B. $ I$ and $III$ only
C. Only $III$
D. $ I$,$II$, and $III$
参考答案:
C
本题详细解析:
Explanation:
Equipotential lines are perpendicular to field lines, which means the field lines must be directed from A to B or vice versa. That is only possible for 2 charges with opposite sign. In I and II, the forces from the two objects would be in opposite directions, giving a resultant field zero at the midpoint, and equipotential lines of a “peanut” shape.