The conducting spherical shells shown in the figure are connected by a conductor. The capacitance of the system is

818-623

  • A

    $4\pi {\varepsilon _0}\,\frac{{ab}}{{b - a}}$

  • B

    $4\pi {\varepsilon _0}\,a$

  • C

    $4\pi {\varepsilon _0}\,b$

  • D

    $4\pi {\varepsilon _0}\,\frac{{{a^2}}}{{b - a}}$

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