A ball is suspended bu an insulated thread. When a positively- charged rod os placed near the ball, the ball woll be attracted towards the rod. What can be concluded from te above case?
a) the ball may carry positive charge.
b) the ball may be neutral
c) the ball may carry negative charge.
The answer is b and c
我想問點解個波唔可以有positive charge
我既意思係如果個波有相同的positive charge同negative charge,個波一樣係中性,但點解a 錯?