For the resultant of two vectors to be maximum,what must be the angle between them? $(^o)$

What is the uncertainty in the velocity of an electron if the uncertainty in the measurement of its position is $50 \text{ pm}$? $(m_e = 9.1 \times 10^{-31} \text{ kg}, h = 6.63 \times 10^{-34} \text{ Js}, \pi = 3.142)$

Which of the following quantity/quantities are dependent on the choice of orientation of the co-ordinate axes?
$(a)$ $\vec{a}+\vec{b}$
$(b)$ $3a_x+2b_y$
$(c)$ $(\vec{a}+\vec{b}-\vec{c})$

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

The vector sum of two forces $\vec{A}$ and $\vec{B}$ is perpendicular to their vector difference. Hence,the forces $\vec{A}$ and $\vec{B}$ are

Explain position and displacement vectors. How is the magnitude of a vector quantity represented?