The surface charge density of a thin charged disc of radius R is σ. The value of the electric field at the centre of the disc is (σ)/(2 ε_o). With…

The surface charge density of a thin charged disc of radius $\displaystyle R$ is $\displaystyle \sigma$. The value of the electric field at the centre of the disc is $\displaystyle \frac{\sigma}{2 \epsilon_{\mathrm{o}}}$. With respect to the field at the centre, the electric field along the axis at a distance R from the centre of the disc :