Five equal forces of $10 \, N$ each are applied at one point and all are lying in one plane. If the angles between them are equal,the resultant force will be ........... $N$.

If $\theta$ is the angle between two vectors $\vec{A}$ and $\vec{B}$,then match the following two columns.

Column $I$	Column $II$
$(A)$ $\vec{A} \cdot \vec{B} = |\vec{A} \times \vec{B}|$	$(p)$ $\theta = 45^{\circ}$ or $135^{\circ}$
$(B)$ $\vec{A} \cdot \vec{B} = B^2$	$(q)$ $\theta = 0^{\circ}$
$(C)$ $|\vec{A} + \vec{B}| = |\vec{A} - \vec{B}|$	$(r)$ $\vec{A} = \vec{B}$
$(D)$ $|\vec{A} \times \vec{B}| = AB$	$(s)$ $\theta = 90^{\circ}$

$100$ coplanar forces,each equal to $10 \ N$,act on a body. Each force makes an angle of $\pi/50$ radians with the preceding force. What is the resultant of the forces in $N$?

If $\vec{A} = 3\hat{i} + 4\hat{j}$ and $\vec{B} = 6\hat{i} + 8\hat{j}$,where $A$ and $B$ are the magnitudes of vectors $\vec{A}$ and $\vec{B}$ respectively,which of the following is incorrect?

$A$ vector $\vec{A}$ having magnitude $6$ units is added to vector $\vec{B}$,which is along the $x$-axis. The resultant of $\vec{A}$ and $\vec{B}$ is along the $y$-axis. If the magnitude of the resultant of $\vec{A}$ and $\vec{B}$ is three times that of $\vec{B}$,then the magnitude of $\vec{B}$ is:

Given $A = 3 \hat{i} + 4 \hat{j}$ and $B = 6 \hat{i} + 8 \hat{j}$,which of the following statements is correct?