What is the position vector of a particle located at $(3, 2, 5)$?

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

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

An object is subjected to a force in the north-east direction. To balance this force,a second force should be applied in the direction:

The position of a particle in a rectangular coordinate system is $(3, 2, 5)$. Then its position vector will be

Assertion $A$: If $A, B, C, D$ are four points on a semi-circular arc with centre at $O$ such that $|\overrightarrow{AB}|=|\overrightarrow{BC}|=|\overrightarrow{CD}|$,then $\overrightarrow{AB}+\overrightarrow{AC}+\overrightarrow{AD}=4\overrightarrow{AO}+\overrightarrow{OB}+\overrightarrow{OC}$.
Reason $R$: Polygon law of vector addition yields $\overrightarrow{AB}+\overrightarrow{BC}+\overrightarrow{CD}+\overrightarrow{AD}=2\overrightarrow{AO}$.
In the light of the above statements,choose the most appropriate answer from the options given below.

If the vector $\vec{P} = 3\hat{i} + 4\hat{j} + 12\hat{k}$,then the magnitude of the vector $\vec{P}$ is ......