A sphere of radius $R$ and charge $Q$ is placed inside a concentric imaginary sphere of radius $2R$. The flux associated with the imaginary sphere is
$\frac{Q}{{{\varepsilon _0}}}$
$\frac{Q}{{{2\varepsilon _0}}}$
$\frac{Q}{{{3\varepsilon _0}}}$
$\frac{Q}{{{4\varepsilon _0}}}$
If the number of electric lines of force emerging out of a closed surface is $1000$ , then the charge enclosed by the surface is .......... $C$
Sketch the electric field lines for a uniformly charged hollow cylinder shown in figure.
Electric flux through a surface of area $100$ $m^2$ lying in the $xy$ plane is (in $V-m$) if $\vec E = \hat i + \sqrt 2 \hat j + \sqrt 3 \hat k$
A cube is placed inside an electric field, $\overrightarrow{{E}}=150\, {y}^{2}\, \hat{{j}}$. The side of the cube is $0.5 \,{m}$ and is placed in the field as shown in the given figure. The charge inside the cube is $.....\times 10^{-11} {C}$
A cube of side $l$ is placed in a uniform field $E$, where $E = E\hat i$. The net electric flux through the cube is