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

Two equal positive point charges are kept at points $A$ and $B$. What happens to the electric potential while moving from $A$ to $B$ along the straight line connecting them?

$A$ spherical shell with an inner radius $a$ and an outer radius $b$ is made of conducting material. $A$ point charge $+Q$ is placed at the centre of the spherical shell and a total charge $-q$ is placed on the shell. Assume that the electrostatic potential is zero at an infinite distance from the spherical shell. The electrostatic potential at a distance $R$ $(a < R < b)$ from the centre of the shell is (where $K = \frac{1}{4\pi\varepsilon_0}$):

Identify the incorrect statement.

Two spheres $A$ and $B$ of radius $a$ and $b$ respectively are at the same electric potential. The ratio of the surface charge densities of $A$ and $B$ is

Three concentric spherical metallic shells $A$,$B$,and $C$ of radii $a=7 \ cm$,$b=17 \ cm$,and $c$ $(a < b < c)$ have surface charge densities $\sigma, -\sigma$,and $\sigma$ respectively. If $A$ and $C$ are at the same potential,then the value of $c$ is: (in $cm$)