Dipole Moments

All molecules with polar bonds may not have dipole moment. Explain.

$\mathrm{X}$ is the central atom of ${\mathrm{XO}}_2$ molecule. If dipole moment of the molecule is zero, indicate the hybridisation state of $\mathrm{X}$.

${\mathrm{CO}}_2$ and ${\mathrm{SO}}_2$ are both triatomic molecules. Do they have same dipole moment? Justify your answer.

Dipole moment of ${\mathrm{NF}}_3$ molecule is less than that of ${\mathrm{NH}}_3$ molecule. Explain.

Name two molecules which have net dipole moment.

What is dipole moment? Give its units.