If the electric potential at a distance of $5 \, cm$ from the center of a charged conducting sphere of radius $10 \, cm$ is $V$,then what will be the potential at a point at a distance of $15 \, cm$ from the center?

$A$ spherical charged conductor has surface charge density $\sigma$. The electric field on its surface is $E$ and the electric potential of the conductor is $V$. Now,the radius of the sphere is halved while keeping the charge constant. The new values of the electric field and potential would be:

$A$ hollow conducting sphere of radius $R$ has a charge $(+Q)$ on its surface. What is the electric potential within the sphere at a distance $r = \frac{R}{3}$ from its centre?

$A$ charge $Q$ is uniformly distributed over a long rod $AB$ of length $L$ as shown in the figure. The electric potential at the point $O$ lying at a distance $L$ from the end $A$ is

$A$ solid conducting sphere, having a charge $Q$, is surrounded by an uncharged conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be $V$. If the shell is now given a charge of $-4\, Q$, the new potential difference between the same two surfaces is......$V$.

The electrostatic potential $V$ at a point on the circumference of a thin non-conducting disk of radius $r$ and uniform charge density $\sigma$ is given by the equation $V = 4 \sigma r$. Which of the following expressions correctly represents the electrostatic energy stored in the electric field of a similarly charged disk of radius $R$?