The figure shows the electric field lines of three charges with charges $+1, +1$,and $-1$. The Gaussian surface in the figure is a sphere containing two of the charges. The total electric flux through the spherical Gaussian surface is

If the electric flux entering and leaving an enclosed surface respectively is ${\varphi _1}$ and ${\varphi _2}$,the electric charge inside the surface will be:

For a closed surface $\oint \vec{E} \cdot d\vec{s} = 0$,then:

Five point charges $\frac{1}{\pi}, \frac{2}{\pi}, \frac{3}{\pi}, \frac{4}{\pi}$ and $\frac{-5}{\pi} \ nC$ are located inside a pyramid. The total electric flux through the surface of the pyramid is

An infinitely long uniform line charge distribution of charge per unit length $\lambda$ lies parallel to the $y$-axis in the $y-z$ plane at $z=\frac{\sqrt{3}}{2} a$ (see figure). If the magnitude of the flux of the electric field through the rectangular surface $A B C D$ lying in the $x-y$ plane with its center at the origin is $\frac{\lambda L }{ n \varepsilon_0}$ (where $\varepsilon_0$ is the permittivity of free space),then the value of $n$ is

Consider a region in free space bounded by the surfaces of an imaginary cube having sides of length $a$ as shown in the figure. $A$ charge $+Q$ is placed at the centre $O$ of the cube. $P$ is a point outside the cube such that the line $OP$ perpendicularly intersects the surface $ABCD$ at $R$, and $OR = RP = a/2$. $A$ charge $+Q$ is also placed at point $P$. What is the total electric flux through the five faces of the cube other than $ABCD$?