$A$ unit positive charge has to be brought from infinity to a midpoint between two charges $20 \mu C$ and $10 \mu C$ separated by a distance of $50 \ m$. How much work will be required?

$A$ non-conducting ring of radius $0.5\,m$ carries a total charge of $1.11 \times 10^{-10}\,C$ distributed non-uniformly on its circumference,producing an electric field $\vec{E}$ everywhere in space. The value of the line integral $\int_{l = \infty }^{l = 0} { - \vec{E} \cdot d\vec{l} }$ (where $l = 0$ is the centre of the ring) in volts is:

$A$ uniform electric field vector $E$ exists along the horizontal direction as shown. The electric potential at $A$ is $V_A$. $A$ small point charge $q$ is slowly moved from $A$ to $B$ along the curved path as shown. The potential energy of the charge when it is at point $B$ is

The mass of a particle is $400$ times that of an electron and its charge is double that of an electron. The particle is accelerated by a potential difference of $5 \; V$. If the particle was initially at rest,what will be its final kinetic energy in $eV$?

$A$ charge of $5\,C$ is given a displacement of $0.5\,m$. The work done in the process is $10\,J$. The potential difference between the two points will be.......$V$

Two isolated,concentric,conducting spherical shells have radii $R$ and $2R$ and uniform charges $q$ and $2q$ respectively. If $V_1$ and $V_2$ are potentials at points located at distances $3R$ and $\frac{R}{2}$,respectively,from the centre of the shells,then the ratio $\left(\frac{V_2}{V_1}\right)$ will be: