Four point charges `+q,+q,-q and -q` are placed on the corners of a square of side length 'a' as shown in the figure. The magnitude of electric field at a point which is at a distance `x (gt gt a)` from the centre along a line perpendicular to the plane of the square and passing through the centre is

Options

A. `(sqrt(2)qa)/(4pi epsilon_()x^(2))`
B. `(qa)/(2pi epsilon_(0)x^(3))`
C. `(sqrt(2)qa)/(2pi epsilon_(0)x^(3))`
D. `(qa)/(4pi epsilon_(0)x^(3))`

Answer

B