If the force exerted by an electric dipole on a charge q at a distance of 1 m is F, the force at a point 2 m away in the same direction will be

Options

(a) F/2
(b) F/4
(c) F/6
(d) F/8

Correct Answer:

F/8

Explanation:

Field of a dipole at a distance d along the axis or perpendicular to the axis is inversely proportional to r³. That is F/8 is the force at the given point, 2 m away if F is the force at 1 m, on the same charge q.