Gauss Law Questions

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:

Statement - 1: For a mass $M$ kept at the centre of a cube of side ‘$a$ ’, the flux of gravitational field passing through its sides is $4\pi GM$.Statement - 2: If the direction of a field due to a point source is radial and its dependence on the distance ‘$r$ ’ for the source is given as $1/r^2$, its flux through a closed surface depends only on the strength of the source enclosed and not on the size or shape of the surface.

Let $\rho (r)=\frac{Qr}{\pi R^4}$ be the charge density distribution for a solid sphere of radius $R$ and total charge $Q$. For a point '$p$ ' inside the sphere at distance $r_1$ from the centre of the sphere, the magnitude of electric field is:

The electrostatic potential inside a charged spherical ball is given by $\varphi =a{r}^2+b$ where $r$ is the distance from the centre; $a,b$ are constants. Then the charge density inside ball is: