Which of the following molecules has zero dipole moment?

Which of the following is non-polar?

Fluorine is more electronegative than either boron or phosphorus. What conclusion can be drawn from the fact that $BF_3$ has no dipole moment but $PF_3$ does?

If $Q$ is the magnitude of charge and $r$ is the distance between the centres of positive and negative charges,then the dipole moment $(\mu)$ is given by:

Which of the following compounds exhibits a dipole moment?

Although both $CO_{2}$ and $H_{2}O$ are triatomic molecules,the shape of $H_{2}O$ molecule is bent while that of $CO_{2}$ is linear. Explain this on the basis of dipole moment.