If the potential of the inner shell of radius $r$ is $10\,V$ and that of the outer shell of radius $2r$ is $5\,V$, then the potential at the centre will be....$V$

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

$A$ particle of mass $m$ and charge $q$ is accelerated through a potential difference of $V$ volt. Its energy is

If a $10 \mu C$ charge exists at the centre of a square,the work done in moving a $2 \mu C$ point charge from corner $A$ to corner $B$ of a square $ABCD$ is

When a charge of $0.01 \ C$ is moved from point $A$ to point $B$ against an electric field,the work done is $15 \ J$. The potential difference $(V_B - V_A)$ is ....... $V$.

There is a uniformly charged non-conducting solid sphere made of material of dielectric constant $1$. If the electric potential at infinity is zero,then the potential at its surface is $V$. If we take the electric potential at its surface to be zero,then the potential at the centre will be