Two points $P$ and $Q$ are maintained at the potentials of $10 \ V$ and $-4 \ V$,respectively. The work done in moving $100$ electrons from $P$ to $Q$ is

Two point charges are located on the $x$-axis. $q_1 = -1 \ \mu C$ at $x = 0$ and $q_2 = +1 \ \mu C$ at $x = 1 \ m$. Find the work done in bringing a third charge $q_3 = +1 \ \mu C$ from infinity to $x = 2 \ m$.

$A$ long,hollow conducting cylinder is kept coaxially inside another long,hollow conducting cylinder of larger radius. Both the cylinders are initially electrically neutral.

An electric dipole is placed as shown in the figure. The electric potential (in $10^2 \ V$) at point $P$ due to the dipole is ($\epsilon_0 =$ permittivity of free space and $\frac{1}{4 \pi \epsilon_0} = K$):

$A$ conductor with a positive charge:

$A$ point charge $q$ is held at the centre of a circle of radius $r$. $B$ and $C$ are two points on the circumference of the circle,and $A$ is a point outside the circle. If $W_{AB}$ represents the work done by the electric field in taking a charge $q_0$ from $A$ to $B$,and $W_{AC}$ represents the work done from $A$ to $C$,then: