Is electrostatic potential a vector or a scalar quantity?

Distinguish between electric potential and electric potential energy.

If the electric potential of the inner metal sphere of radius $a$ is $10 \text{ V}$ and that of the outer spherical shell of radius $b$ is $5 \text{ V}$,then the potential at the centre will be ...... $\text{V}$.

An electron enters a high potential region $V_2$ from a lower potential region $V_1$. What happens to its velocity?

$A$ pellet carrying a charge of $0.5\, C$ is accelerated through a potential difference of $2,000\, V$. What is the kinetic energy attained by the pellet?

$A$ point charge $q$ of mass $m$ is placed at the center of a ring of radius $R$ carrying a charge $Q$. When it is slightly displaced,the point charge accelerates to infinity along the $x$-axis. The ultimate speed of the point charge is .......