The static electrical field inside a dielectric medium with relative permittivity, $\varepsilon _{r}= 2.25$, expressed in cylindrical coordinate system is given by the following expression

$E= a_{r}2r+a_{\varphi }\left(\frac{3}{r}\right)+a_{z}\: 6$

where $a_{r},a_{\varphi },a_{z}$ are unit vectors along $r,\varphi$ and $z$ directions, respectively. If the above expression represents a valid electrostatic field inside the medium, then the volume charge density associated with this field in terms of free space permittivity, $\varepsilon _{0}$, in SI units is given by:

1. $3\varepsilon _{0}$
2. $4\varepsilon _{0}$
3. $5\varepsilon _{0}$
4. $9\varepsilon _{0}$
in Others
edited