B M Sharma Solutions for Chapter: Electric Potential, Exercise 1: DPP

Three charges $2q$, $-q$ and $-q$ are located at the vertices of an equilateral triangle. At the centre of the triangle.

Two electric charges $12 \mathrm{\mu C}$ and $-6 \mathrm{\mu C}$ are placed $20 \mathrm{cm}$ apart in the air. There will be a point $P$ on the line joining these charges and outside the region between them, at which the electric potential is zero. The distance of $P$ from $-6 \mathrm{\mu C}$ charge is

A spherical conductor of radius $2 \mathrm{m}$ is charged to a potential of $120 \mathrm{V}$. It is now placed inside another hollow spherical conductor of radius $6 \mathrm{m}$. Calculate the potential to which the bigger sphere would be raised.

Two point charges $100 \mathrm{\mu C}$ and $5 \mathrm{\mu C}$ are placed at points $A$ and $B$ respectively with $AB=40 \mathrm{cm}$. Find the work done by external force in displacing the charge $5 \mathrm{\mu C}$ from $B$ to $C$ where $BC=30 \mathrm{cm}$, angle $ABC=\frac{\mathrm{\pi }}{2}$ and, $\frac{1}{4\mathrm{\pi }{\epsilon }_0}=9\times {10}^9 {\mathrm{Nm}}^2 {\mathrm{C}}^{-2}$.

In the rectangle, shown below, the two corners have charges $q_1=-5 \mathrm{\mu C}$ and $q_2=+2.0 \mathrm{\mu C}$. The work done in moving a charge $+3.0 \mathrm{\mu C}$ from $B$ to $A$ is (take $1/4\mathrm{\pi }{\epsilon }_0={10}^{10} {\mathrm{Nm}}^2 {\mathrm{C}}^{-2}$ )

A charge $\left(-q\right)$ and another charge $\left(+q\right)$ are kept at two points $A$ and $B$ respectively. Keeping the charge $\left(+Q\right)$ fixed at $B$, the charge $\left(-q\right)$ at $A$ is moved to another point $C$ such that, $ABC$ forms an equilateral triangle of side $L$. The net work done in moving the charge $\left(-q\right)$ is

A point charge is surrounded symmetrically by six identical charges at distance $r$ as shown in the figure. How much work is done by the forces of electrostatic repulsion when the point charge $q$ at the centre is removed at infinity?

An electric field $E$ whose direction radially outward varies as distance from the origin $r$ as shown in the graph. $E$ is taken as positive if its direction is away from the origin. Then the work done by the electric field on a $2 \mathrm{C}$ charge if it is taken from $\left(1, 1, 0\right)$ to $\left(3, 0, 0\right)$ is