Which of the following compounds has a permanent dipole moment?

Statement $I$: Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the positive centre and head pointing towards the negative centre.
Statement $II$: The crossed arrow of the dipole moment symbolizes the direction of the shift of charges in the molecules.
In the light of the above statements,choose the most appropriate answer from the options given below :-

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $NH_3$ and $NF_3$ molecules have a pyramidal shape with a lone pair of electrons on the nitrogen atom. The resultant dipole moment of $NH_3$ is greater than that of $NF_3$.
Reason $R$: In $NH_3$,the orbital dipole due to the lone pair is in the same direction as the resultant dipole moment of the $N-H$ bonds. $F$ is the most electronegative element.

What is the physical shape and dipole moment of $H_2S$?

Which molecule has the maximum dipole moment $\mu$? (where $X = -NO_2$)

If $HCl$ were purely ionic,its expected dipole moment would be $6.12 \, D$. However,the experimental dipole moment is $1.03 \, D$. Calculate the percentage ionic character. (in $\%$)