1. The problem statement, all variables and given/known data Four charges are arranged on the corner of a square. At which points is the electric field equal to zero? Diagram: http://img126.imageshack.us/img126/1994/diagram2zb7.png [Broken] 2. Relevant equations None 3. The attempt at a solution I chose A and B because the charges are equal so therefore the electric field will be zero right inbetween them.