1. 2 Electric field intensity Discussion: Originally, the concept of field was introduced by the Convenience of treatment. It was later found out that the field does exist 1.2.1 Definition: E Test charge Q would not alter the field 1.2.2E produced by different shape of charges 1)Point shape charge E=∑ 2)Linear shape charge E=1,A(F)0 4 兀E1. 2 Electric field intensity Discussion: Originally , the concept of field was introduced by the Convenience of treatment. It was later found out that the field does exist. 1.2.1.Definition: Q F E   = 1.2.2 E produced by different shape of charges r dl r r E l 0 2 0 ( ) 4 1     =    2) Linear shape charge: 1)Point shape charge: 0 1 2 i n i i i r r Q E   = = Test charge Q would not alter the field