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

Which of the following has the highest dipole moment?

$A$ diatomic molecule has a dipole moment of $1.2 \ D$. If the bond distance is $1 \ \mathring{A}$,then fractional charge on each atom is.........$\times 10^{-2}$ (Given $1 \ D = 10^{-18} \ esu \ cm$ )

If $H-X$ bond length is $2 \ \mathring{A}$ and $H-X$ has dipole moment $5.12 \times 10^{-30} \ C \cdot m$,the $\%$ of covalent character of the molecule is ............. $\%$

Which of the following compounds exhibits a dipole moment?