`CO_(2) and H_(2)O` both are triatomic molecules but their dipole moment values are different. Why?

Explanation

In `CO_(2)` there are two C-0 bonds. Each C=O bond is a polar bond.
The net dipole moment of `CO_(2)` molecule is zero. This is possible only if `C_(2)` is a linear molecule. (O = C = O). The bond dipóles of two C = 0 bonds cancels the dipole moment of each other.
Whereas, `H_(2)O` molecule has a net dipole moment (1.84 D). `H_(2)O` molecule has a bent structure because here the O - H bonds are oriented at an angle of `104.5^(@)` and do not cancel the bond dipole moments os each other.