The magnitude of the average electric field normally present in the atmosphere just above the surface of the Earth is about $150\, N/C$, directed inward towards the center of the Earth . This gives the total net surface charge carried by the Earth to be......$kC$ [Given ${\varepsilon _0} = 8.85 \times {10^{ - 12}}\,{C^2}/N - {m^2},{R_E} = 6.37 \times {10^6}\,m$]

As shown in figure, a cuboid lies in a region with electric field $E=2 x^2 \hat{i}-4 y \hat{j}+6 \hat{k} \quad N / C$. The magnitude of charge within the cuboid is $n \varepsilon_0 C$. The value of $n$ is $............$ (if dimension of cuboid is $1 \times 2 \times 3 \;m ^3$ )

An electric field is given by $(6 \hat{i}+5 \hat{j}+3 \hat{k}) \ N / C$.

The electric flux through a surface area $30 \hat{\mathrm{i}}\; m^2$ lying in $YZ-$plane (in SI unit) is

What is the flux through a cube of side $a$ if a point charge of $q$ is at one of its comer? 

What will be the total flux through the faces of the cube as in figure with side of length $'a'$ if a charge $'q'$ is placed at ?

$(a)$ $C$ $:$ centre of a face of the cube.

$(b)$ $D$ $:$ midpoint of $B$ and $C$.

Assertion : Electric lines of force never cross each other.

Reason : Electric field at a point superimpose to give one resultant electric field.