In many situations, to find the electric field using the gauss law, we can use the simplified equation $\left|\overrightarrow{E}\right|=\frac{q_{\mathrm{enclosed}}}{{\epsilon }_0\left|\overrightarrow{A}\right|}$, where ${\epsilon }_0$ is the permittivity of free space, $A$ is the area of Gaussian surface and $q_{\mathrm{enclosed}}$ is the net charge enclosed by the Gaussian surface. Among the following situations, this equation can be used