12. 10C (Coulomb) of charge are placed on a spherical conducting shell. A particle with a charge of -3C is placed at the center of the cavity. The net charge on the outer surface of the shell is:

(A)-7C

(B)-3C

(C)0C

(D)+3C

(E)+7C

答案:登入後查看
統計: 尚無統計資料