The unequal sharing of bonded pair of electrons between two atoms in a molecule causes

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 will show a dipole moment?

Which of the following is polar?

Which of the following molecules have non-zero dipole moments?
$I$. Gauche conformation of $1, 2$-dibromoethane
$II$. Anti conformation of $1, 2$-dibromoethane
$III$. Trans-$1, 4$-dibromocyclohexane
$IV$. Cis-$1, 4$-dibromocyclohexane
$V$. Tetrabromomethane
$VI$. $1, 1$-dibromocyclohexane

Dipole moment of $HCl = 1.03 \ D$ and $HI = 0.38 \ D$. Bond length of $HCl = 1.3 \ \mathring{A}$ and $HI = 1.6 \ \mathring{A}$. The ratio of the fraction of electric charge,$\delta$,existing on each atom in $HCl$ and $HI$ is: