Which of the following molecules has the highest dipole moment?

The dipole-dipole interaction energy between polar molecules in the solid state will be proportional to ...... [if $r$ denotes the distance between polar molecules]

Which molecule has a zero dipole moment?

Which bond is more polar in the following pairs of molecules: $(a)$ $H_3C-H, H_3C-Br$ $(b)$ $H_3C-NH_2, H_3C-OH$ $(c)$ $H_3C-OH, H_3C-SH$

Given below are two statements:
Statement-$I$: Since fluorine is more electronegative than nitrogen,the net dipole moment of $NF_3$ is greater than $NH_3$.
Statement-$II$: In $NH_3$,the orbital dipole due to lone pair and the dipole moment of $N-H$ bonds are in opposite direction,but in $NF_3$ the orbital dipole due to lone pair and dipole moments of $N-F$ bonds are in same direction.
In the light of the above statements,choose the most appropriate from the options given below.

Which of the following compounds has a permanent dipole moment?