There is a ball (A) is carrying a uniformly distributed unknown charge(wich may be zero) and an uncharged copper ball (D). A positive test charge (T) experiences highly attraction with ball (A) and (D). What is the nature of the force between balls A and D if they are brought very close together? Choices are attractive repulsive no force What I think the answer should be is repulsive because since (T) is strongly attacted to both balls, that means both balls must have a same charge; therefore repel when brought close together. However it says in the problem that the copper ball (D) is uncharged. What does that mean? It has equal amount of electrons and protons? Also what does copper come to play here? I know it is an extremely good conductor of electricity but does this fact play an important role in this question? Thank you for your help.