CO2 is a linear molecule the dipole moment arising due to two atoms are opposite in the direction of always cancels each other and since there is no net dipole moment in seo2 molecule due to its linear structure it is called no dipole moment in CO2.

BY THE DEFINITION OF DIPOLE MOMENT IT IS PRODUCT OF CHARGE AND DISTANCE BETWEEN THEM AND IT HAS DIRECTION FROM MINUS TO PLUS CHARGE BUT DUE TO EQUAL IN MAGNITUDE AND OPPOSITE IN DIRECTION IT GOT CANCEL IN CO2