Which describes the dipole moment vector and the electric fi

Which describes the dipole moment vector and the electric field at a point on the dipole axis, outside the dipole?

a. The two vectors are in the same direction.

b. The two vectors are in opposite directions.

c. Outside the positive end of the dipole, the two vectors are in the same direction. Outside the negative end, they are in opposite directions.

d. Outside the negative end of the dipole, the two vectors are in the same direction. Outside the positive end, they are in opposite directions.

Please give reasons for your answer.

Solution

in the case of electric dipole we have 2 electric charges seperated by a distance l, 2 electric charges are opposite in nature the one is +ve charge and the other is -ve charge and the dipole moment is given as:

p = q*l (charge multiplied by the distance of seperation) where p repersents the moment of dipole, please dont confuse p with the momentum as they both are repersented by p,

Now, electric dipole moment as it a vector quantity it means it has both direction as well as the magnitude.

direction of the moment vector is always from -ve charge to the +ve charge. (for the case of charges.), whereas for the case of atoms/ molecules dipole moment vector is always from +ve to -ve (for molecules) but here we are taking about charges so the direction will be towards +q charge and moving out of +q charge.

whereas for the case of electric field vector it will be outside direction from both +ve as well as -ve charges.electric field vector will be coming outside from +ve and -ve.

So this means Outside the +ve end of the dipole, two vectors are in same direction, whereas outside the -ve end they are in opposite directions so the answer will be C.

Thanks