A conducting sphere of radius $0.1 \mathrm{m}$ has a uniform positive charge density of $1.8 \mu \mathrm{C}/{\mathrm{m}}^2$ on its surface. The electric field in $\mathrm{V}/\mathrm{m}$ in free space at a radial distance of $0.2 \mathrm{m}$ from a point on the surface of the sphere is given by

Two conducting spheres of radii $r_{1}$ and $r_{2}$ are charged to the same surface charge density. The ratio of electric field near their surface is

A charge $Q=1.8 \mu \mathrm{C}$ is placed at the centre of a cube of edge $55 \mathrm{cm}$. The electric flux through one of the faces of the cube is

The electric field in a region is radially outward with magnitude $E=\frac{A}{{\gamma }_0}$. The charge contained in a sphere of radius ${\gamma }_0$, centered at the origin is

Cylinder is charged by $10 \mathrm{mC}$. Length of cylinder is $1 \mathrm{km}$ and radius is $1 \mathrm{mm}$. Surface charge density of cylinder is

A metal of surface area $1 {\mathrm{m}}^2$ is charged with $\sqrt{8.85} \mu \mathrm{C}$ in air. The mechanical force acting on it is (Use:${\epsilon }_0=8.85\times {10}^{-12} \mathrm{F} {\mathrm{m}}^{-1}$

The surface density of charge on the surface of a charged conductor in air is $0.885 \mathrm{\mu C} {\mathrm{m}}^{-2}$. If ${\epsilon }_0=8.85\times {10}^{-12} {\mathrm{C}}^2 {\mathrm{N}}^{-1} {\mathrm{m}}^{-2}$ then the outward force per unit area of the charged conductor is

A metal sphere of radius $10 \mathrm{cm}$ is given a charge of $12 \mathrm{\mu C}$. The force acting on unit area of its surface is

The energy density per unit volume of medium in an electric field of intensity $400 \mathrm{V} {\mathrm{m}}^{-1}$ is (dielectric constant of material is $2$ and $\varepsilon_{0}=8.85 \times 10^{-12}$ units $)$