$A$ particle of charge $Q$ and mass $m$ travels through a potential difference $V$ from rest. The final momentum of the particle is

Two charges $5 \times 10^{-8} \; C$ and $-3 \times 10^{-8} \; C$ are located $16 \; cm$ apart. At what point$(s)$ on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.

Assertion $(A)$: The work done by the electrostatic force is zero when a point charge moves in a circular path around another charge.
Reason $(R)$: The dot product of force and displacement vectors gives work done.

As shown in the figure,positive and negative charges of $1\ \mu C$ are placed at two points. Find the potential difference between $A$ and $B$ in $volt$.

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

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