Four point charges ( + 4Q), (- 2Q) and (+Q) and (-Q) with Q > 0 arc placed as shown in the figure. Find the magnitude and direction of the net electric field at the origin O of the system of coordinates What would be the magnitude an direction of the electric force acting, on a charge (- Q ) which is placed at the origin? Repeat for a charge (+Q). If the charge (-2Q) is removed from the x axis what will be the magnitude and the direction of the electric field produced b y the remaining 3 charges at point O?