A charge of total amount $Q$ is distributed over two concentric hollow spheres of radii $r$ and $R ( R > r)$ such that the surface charge densities on the two spheres are equal. The electric potential at the common centre is

  • [AIEEE 2012]
  • [IIT 1981]
  • [JEE MAIN 2020]
  • A

    $\frac{1}{{4\pi {\varepsilon _0}}}\frac{{\left( {R - r} \right)Q}}{{\left( {{R^2} + {r^2}} \right)}}$

  • B

    $\frac{1}{{4\pi {\varepsilon _0}}}\frac{{\left( {R + r} \right)Q}}{{2\left( {{R^3} + {r^3}} \right)}}$

  • C

    $\frac{1}{{4\pi {\varepsilon _0}}}\frac{{\left( {R + r} \right)Q}}{{\left( {{R^2} + {r^2}} \right)}}$

  • D

    $\frac{1}{{4\pi {\varepsilon _0}}}\frac{{\left( {R - r} \right)Q}}{{2\left( {{R^2} + {r^2}} \right)}}$

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