Point charges each of magnitude $Q$ are placed at three corners of a square as shown in the diagram. What is the direction of the resultant electric field at the fourth corner ?

If electric lines of force in a region are represented as shown in the figure, then one can conclude that the electric field is

An uncharged sphere of metal is placed in a uniform electric field produced by two oppositely charged plates. The lines of force will appear as

Figure shows electric lines of forces due to charges $Q_1$ and $Q_2.$ Hence

Figure shows electric lines of force. If $E_x$ and $E_y$ are the magnitudes of electric field at points $x$ and $y$ respectively, then