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

If $\vec{A}$ and $\vec{B}$ are two non-zero vectors such that $|\vec{A} + \vec{B}| = \frac{|\vec{A} - \vec{B}|}{2}$ and $|\vec{A}| = 2|\vec{B}|$,then the angle between $\vec{A}$ and $\vec{B}$ is

$ABC$ is an equilateral triangle. The length of each side is $a$ and the centroid is point $O$. If $\overrightarrow{AB} + \overrightarrow{AC} = n \overrightarrow{AO}$,then find the value of $n$.

What is a position vector? What is a displacement vector? Explain the equality of vectors.

What is the minimum number of non-zero vectors in different planes that can be added to give a zero resultant?

$A$ vector $\overrightarrow{a}$ is turned without a change in its length through a small angle $d\theta$. The values of $|\Delta \overrightarrow{a}|$ and $\Delta a$ are respectively: