The minimum work needed to be done to bring a charge $q=6 \mu C$ from $\infty$ to a point $0.75 \ m$ from a charge $Q=30 \mu C$ is (in $J$)

The potential difference $(V_A-V_B)$ in the arrangement shown in the figure is $(q=1 \mu C, x=2 \text{ cm}, y=3 \text{ cm})$.

Derive an expression for the electric potential at a point due to a system of $N$ charges.

$A$ bullet of mass $2\,g$ has a charge of $2\,\mu C$. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of $10\,m/s$?

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

In a certain charge distribution,all points having zero potential can be joined by a circle $S$. Points inside $S$ have positive potential and points outside $S$ have negative potential. $A$ positive charge,which is free to move,is placed inside $S$. What will happen to the charge?