Questions in vectors

Select	Question
	When $\vec A.\vec B = - \|A\|\|B\|,$ then
	If $\|\vec A \times \vec B\| = \sqrt 3 \vec A.\vec B,$ then the value of$\|\vec A + \vec B\|$ is
	A force $\vec F = 3\hat i + c\hat j + 2\hat k$ acting on a particle causes a displacement $\vec S = - 4\hat i + 2\hat j - 3\hat k$ in its own direction. If the work done is 6J, then the value of c will be
	A force $\vec F = (5\hat i + 3\hat j)\;N$is applied over a particle which displaces it from its original position to the point $\vec s = (2\hat i - 1\hat j)$m. The work done on the particle is
	If a vector $\vec A$ is parallel to another vector $\vec B$ then the resultant of the vector $\vec A \times \vec B$ will be equal to