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

Two concentric hollow spherical shells have radii $r$ and $R$ $(R \gg r)$. $A$ charge $Q$ is distributed on them such that the surface charge densities are equal. The electric potential at the centre is

Two isolated,concentric,conducting spherical shells have radii $R$ and $2R$ and uniform charges $q$ and $2q$ respectively. If $V_1$ and $V_2$ are potentials at points located at distances $3R$ and $\frac{R}{2}$,respectively,from the centre of the shells,then the ratio $\left(\frac{V_2}{V_1}\right)$ will be:

Which of the following statements is correct?

$A$ hemispherical bowl of radius $R$ is uniformly charged with surface charge density $\sigma$. Find the electric potential at point $A$,which lies on the base at a distance $R/2$ from the center $O$ of the base.

What is the electric potential at a distance of $9 \text{ cm}$ from a charge of $3 \text{ nC}$ (in $\text{ V}$)?