The electric field at $2 R$ from the centre of a uniformly charged non-conducting sphere of radius $R$ is $E.$ The electric field at a distance $\frac{R}{2}$ from the centre will be

$ABC$ is an equilateral triangle. Charges $+q$ are placed at each corner. The electric field intensity at the centroid of triangle will be

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