A solid conducting sphere of radius $a$ has a net positive charge $2Q$. A conducting spherical shell of inner radius $b$ and outer radius $c$ is concentric with the solid sphere and has a net charge $-Q$. The surface charge density on the inner and outer surfaces of the spherical shell will be
  • A$ - \frac{{2Q}}{{4\pi {b^2}}},\frac{Q}{{4\pi {c^2}}}$
  • B$ - \frac{Q}{{4\pi {b^2}}},\frac{Q}{{4\pi {c^2}}}$
  • C$0,\frac{Q}{{4\pi {c^2}}}$
  • D
    None of the above
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