Question

three charges -q -q and q placed corners of equilateral triangle of side l what is dipole moment of system

Answer 1

Please see the pic I have posted....

Answer 2

Answer: $q.l \sqrt 3$

Explanation:

For charges arranged in equilateral triangle, dipole moment is given by:

$R = \sqrt{P^2+P^2+2P.P cos \theta}$

P = q l ( product of charge and distance)

The angle of equilateral triangle is 60°

Thus, $R = \sqrt{(q.l)^2+(q.l)^2+2(q.l)^2 cos 60}=q.l \sqrt 3$