11. We have three identical conducting spheres. Their initial charges are A, +8e； В, +13e； C, -2e. We touch A and C and then move them apart. Then we touch B and C and then move them apart. What then is the final charge on B?
(A) +3e
(B) -e
(C) 0
(D) +8e
(E) +e.

1. 題目解析這道題目要求我們計算三個...