Fields of an extended charge distribution a general distribution of charges in space is usually describec by an electric charge density pl Once p(r) is given, one can calculate the electric fiel e(r) generated E(r\=>Ei +TE0r-r2-I)idr Remarks (1)Application of this expression to get e is techni- cally more complicate, since it involves a summation of vectors (2)There is another way to obtain E more efficiently (thru V)