$A$ sphere of radius $R$ and charge $Q$ is placed inside an imaginary sphere of radius $2R$ whose center coincides with the given sphere. The flux related to the imaginary sphere is

Electric charge is uniformly distributed along a long straight wire of radius $1\, mm$. The charge per $cm$ length of the wire is $Q$ $coulomb$. Another cylindrical surface of radius $50\, cm$ and length $1\, m$ symmetrically encloses the wire as shown in the figure. The total electric flux passing through the cylindrical surface is

The linear charge density of a wire is $8.85\,\mu C/m$. The radius and height of the cylinder are $3\,m$ and $4\,m$ respectively. Find the electric flux passing through the cylinder.

$A$ charge '$Q$' $C$ is placed at the centre of a cube. The electric flux through two opposite faces of the cube is $(\epsilon_0 = \text{permittivity of free space})$

Arrangements of charges are shown in the figure. Flux linked with the closed surfaces $P$ and $Q$ respectively are . . . . . . and . . . . . . .

$A$ charge of $1 \,C$ is located at the centre of a sphere of radius $10 \,cm$ and a cube of side $20 \,cm$. The ratio of outgoing flux from the sphere and cube will be