Two charges of -0.64 C each are located at opposite corners of a square having a side of 0.0225 m. 13. Find the electric field strength at the center of the square. 13. 14. Find the electric field strength at one of the unoccupied corners. 14. The following question is about sketching electric field lines. 15. ChargeA is -3 C, charge B is +3 C, charge C is -6 C and charge D is +6 C. Assume the charges are far enough apart that their fields do not affect one A B C D another. Sketch in the electric field lines about all four charges so that their densities are correct relative to one another. 15._ _In figure