A long cylindrical volume contains a uniformly distributed charge of density $\rho$. The radius of cylindrical volume is $R$. A charge particle $(q)$ revolves around the cylinder in a circular path. The kinetic of the particle is
$\frac{\rho q R^{2}}{4 \varepsilon_{0}}$
$\frac{\rho q R^{2}}{2 \varepsilon_{0}}$
$\frac{q \rho}{4 \varepsilon_{0} R^{2}}$
$\frac{4 \varepsilon_{0} R^{2}}{q \rho}$
A point charge $q$ is placed at a distance $a/2$ directly above the centre of a square of side $a$. The electric flux through the square is
If a charge $q$ is placed at the centre of a closed hemispherical non-conducting surface, the total flux passing through the flat surface would be
An ellipsoidal cavity is carved within a perfect conductor. A positive charge $q$ is placed at the centre of the cavity. The points $A$ and $B$ are on the cavity surface as shown in the figure. Then
Draw electric field lines of simple charge distribution.
If atmospheric electric field is approximately $150 \,volt / m$ and radius of the earth is $6400 \,km$, then the total charge on the earth's surface is .......... coulomb