The electric field \(\overrightarrow{E}\) due to a point charge \(q\) located at the origin of a cylindrical coordinate system is given by:

$$\overrightarrow{E}=\frac{1}{4\pi\varepsilon_0}\frac{q}{r^2}\hat{r}$$

Where:

- \(\varepsilon_0=8.85\times10^{-12}\text{C}^2/\text{Nm}^2\) is the permittivity of free space.

- \(r\) is the distance from the point charge to the observation point.

- \(\hat{r}\) is a unit vector pointing radially outward from the point charge.