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)aq` 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)` aq along `+x` direction

Answer

B