Three particles,each having a charge of $10\,\mu C$,are placed at the corners of an equilateral triangle of side $10\,cm$. The electrostatic potential energy of the system is.....$J$ (Given $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\,N\cdot m^2/C^2$).

Let $V_1$ be the potential at the center of a square of side $1 \ m$ when the charges at the $4$ corners are $2 \ C$ each. If the same charges are placed at the corners of a square of side $2 \ m$,then the potential at the center of this square is $V_2$. The value of $\frac{V_2}{V_1}$ is

Two charges $q_1$ and $q_2$ are separated by a distance of $30\ cm$. $A$ third charge $q_3$,initially at $C$ as shown in the figure,is moved along the circular path of radius $40\ cm$ from $C$ to $D$. If the difference in potential energy due to the movement of $q_3$ from $C$ to $D$ is given by $\frac{q_3 K}{4 \pi \epsilon_0}$,find the value of $K$.

$A, B$ and $C$ are three points in a uniform electric field as shown in the figure. The electric potential 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?

$A$ hollow conducting sphere of radius $R$ carries a charge $(+Q)$ on its surface. Find the electric potential at a distance $r = R/3$ from its center.