Electric field at a point varies as $r^0$ for

Consider a long uniformly charged cylinder having constant volume charge density $\rho$ and radius $R$. $A$ Gaussian surface is in the form of a cylinder of radius $r$ such that the vertical axis of both cylinders coincide. For a point inside the cylinder $(r < R)$,the electric field is directly proportional to

The expression for electric field intensity at a point outside a uniformly charged thin plane sheet is (where $d$ is the distance of the point from the plane sheet):

The electric field intensity due to an infinite cylindrical thin wire having charge $q$ per unit length at a distance $r$ from its axis is

$A$ hollow metal sphere of radius $R$ is uniformly charged. The electric field due to the sphere at a distance $r$ from the centre is:

Three infinitely long charged thin sheets are placed as shown in the figure. The magnitude of the electric field at point $P$ is $\frac{x \sigma}{\epsilon_0}$. The value of $x$ is . . . . . . . (All quantities are measured in $SI$ units).