A uniformly charged disc of radius $R$ having surface charge density $\sigma$ is placed in the ${xy}$ plane with its center at the origin. Find the electric field intensity along the $z$-axis at a distance $Z$ from origin :-

  • [JEE MAIN 2021]
  • A

    ${E}=\frac{\sigma}{2 \varepsilon_{0}}\left(1-\frac{{Z}}{\left({Z}^{2}+{R}^{2}\right)^{1 / 2}}\right)$

  • B

    ${E}=\frac{\sigma}{2 \varepsilon_{0}}\left(1+\frac{{Z}}{\left({Z}^{2}+{R}^{2}\right)^{1 / 2}}\right)$

  • C

    ${E}=\frac{2 \varepsilon_{0}}{\sigma}\left(\frac{1}{\left({Z}^{2}+{R}^{2}\right)^{1 / 2}}+{Z}\right)$

  • D

    ${E}=\frac{\sigma}{2 \varepsilon_{0}}\left(\frac{1}{\left({Z}^{2}+{R}^{2}\right)}+\frac{1}{{Z}^{2}}\right)$

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