Which of the following is a polar compound?

Which of the following compounds does not possess a dipole moment?

Which of the following molecules has the highest dipole moment?

Amongst $BeF_{2}$,$BF_{3}$,$H_{2}O$,$NH_{3}$,$CCl_{4}$ and $HCl$,the number of molecules with non-zero net dipole moment is ...... .

Which of the following will have the maximum dipole moment?

Each of the following options contains a set of four molecules. Identify the option$(s)$ where all four molecules possess a permanent dipole moment at room temperature.
$(1)$ $BeCl_2, CO_2, BCl_3, CHCl_3$
$(2)$ $SO_2, C_6H_5Cl, H_2Se, BrF_5$
$(3)$ $BF_3, O_3, SF_6, XeF_6$
$(4)$ $NO_2, NH_3, POCl_3, CH_3Cl$