The point charges `+ q, -2q` and `+ q` are placed at point `(x = 0, y = a, z = 0), (x = 0, y = 0, z = 0)` and `(x = a, y = 0, z = 0)`, repectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are

Options

A. `sqrt(2) qa` along `+y` direction
B. `sqrt(2) qa` along the line joining points `(x = 0 , y = 0 , z = 0)` and `( x = a , y = a , z = 0)`
C. `qa` along the line joining points `(x = 0 , y = 0 , z= 0)` and `(x = a , y = a , z = 0)`
D. `sqrt(2) qa` along `+x` direction

Answer

2

Explanation

Resultant dipole moment

`P' = sqrt(2) p = sqrt(2) qa`
`theta = 45^(@)`