Match Column $-I$ with Column $-II$.

Column $-I$	Column $-II$
$(1)$ Angular momentum	$(a)$ Scalar
$(2)$ Potential energy	$(b)$ Vector
	$(c)$ Unit vector

Let $\theta$ be the angle between vectors $\vec{A}$ and $\vec{B}$. Which of the following figures correctly represents the angle $\theta$?

Find the unit vector of a vector whose coordinates are $(8, 6)$.

Which of the following statement$(s)$ is/are correct?

The direction cosines of the vector $\hat{i} + \hat{j} + \sqrt{2}\hat{k}$ are:

Given $a+b+c+d=0,$ which of the following statements are correct:
$(a)$ $a, b, c,$ and $d$ must each be a null vector.
$(b)$ The magnitude of $(a+c)$ equals the magnitude of $(b+d)$.
$(c)$ The magnitude of $a$ can never be greater than the sum of the magnitudes of $b, c,$ and $d$.
$(d)$ $(b+c)$ must lie in the plane of $a$ and $d$ if $a$ and $d$ are not collinear,and in the line of $a$ and $d$ if they are collinear.