question____14

Question

Six charges are placed at the certices of a regular hexagon as shown in the figure . The electric field on the line passing through point O and perpendicular to the plane of the figure at a distance x from point O is (x>>a)

Answer 1

Answer : (a) Qa/π∈₀x³

Explanation :

Consider the charges at opposite sides of O . They form a dipole with dipole moment p=2Qa

Electrical field due to a dipole on its axis is E=kp/x³ = Qa/2π∈₀x³

Now three fields exists as shown in figure :

Net electric field :

|Enet|=2|E|

=2Qa/2π∈₀x³ = Qa/π∈₀x³