Two spherical conductors $A$ and $B$ of radii $a$ and $b$ $(b > a)$ are placed concentrically in air. The two are connected by a copper wire as shown in figure. Then the equivalent capacitance of the system is
  • A$4\pi {\varepsilon _0}\frac{{ab}}{{b - a}}$
  • B$4\pi {\varepsilon _0}(a + b)$
  • C$4\pi {\varepsilon _0}b$
  • D$4\pi {\varepsilon _0}a$
AIIMS 2017, Medium
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