Consider the following compounds. Which compound possesses the highest dipole moment?

Among the following,the molecule with the lowest dipole moment is

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 ............. $\%$

Number of compounds/species from the following with non-zero dipole moment is. . . . . . $BeCl_2, BCl_3, NF_3, XeF_4, CCl_4, H_2O, H_2S, HBr, CO_2, H_2, HCl$

Consider the following compounds in the liquid form:
$O_2, HF, H_2O, NH_3, H_2O_2, CCl_4, CHCl_3, C_6H_6, C_6H_5Cl$.
When a charged comb is brought near their flowing stream,how many of them show deflection as per the figure?

Arrange the following molecules from most to least polar ($I$,$II$,$III$,$IV$,$V$ respectively): $CH_4$,$CF_2Cl_2$,$CF_2H_2$,$CCl_4$,$CCl_2H_2$.