In a cuboid of dimension $2 L \times 2 L \times L$, a charge $q$ is placed at the centre of the surface ' $S$ ' having area of $4 L ^2$. The flux through the opposite surface to ' $S$ ' is given by

A charge $'q'$ is placed at one corner of a cube as shown in figure. The flux of electrostatic field $\overrightarrow{ E }$ through the shaded area is …… .

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 ${\varepsilon _0} = 8.85 \times {10^{ – 12}}\,{C^2}/N – {m^2},{R_E} = 6.37 \times {10^6}\,m$]

The figure shows some of the electric field lines corresponding to an electric field. The figure suggests

What is the net flux of the uniform electric field of $E =3 \times 10^{3} i\; N / C $ through a cube of side $20\; cm$ oriented so that its faces are parallel to the coordinate planes?