If $\overrightarrow R$ is the resultant vector of two vectors $\overrightarrow A $ and $\overrightarrow B $, then  $\overrightarrow {\left| R \right|} \,...\,\overrightarrow {\left| A \right|} \, + \,\overrightarrow {\left| B \right|} $.

Which of the following quantity/quantities are dependent on the choice of orientation of the co-ordinate axes?

$(a)$ $\vec{a}+\vec{b}$

$(b)$ $3 a_x+2 b_y$

$(c)$ $(\vec{a}+\vec{b}-\vec{c})$

What is the meaning of substraction of two vectors ?

When vector $\overrightarrow{ A }=2 \hat{ i }+3 \hat{ j }+2 \hat{ k }$ is subtracted from vector $\vec{B}$, it gives a vector equal to $2 \hat{j}$. Then the magnitude of vector $\vec{B}$ will be:

The resultant of two vectors at an angle $150^{\circ}$ is $10$ units and is perpendicular to one vector. The magnitude of the smaller vector is ....... units

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 $\overrightarrow{A B}+\overrightarrow{B C}+\overrightarrow{C D}+\overrightarrow{A D}=2 \overrightarrow{A O}$

In the light of the above statements, choose the most appropriate answer from the options given below