Magnitude of the dipole moment is
When we place an electric dipole of point charges
#vecp = q vecs#
#vecs#is the displacement vector which points from the negative charge to the positive charge.
The electric dipole moment vector
Inserting given values we get
Given electric field will be required if we need to find out torque exerted by the electric field on the dipole. Also remember that the torque on the dipole will be zero when the dipole moment is pointing in the same direction of the electric field.