Two spherical conductors `A` and `B` of radii `a` and `b (b gt a)` ar placed concentrically in air. The two are connected by a copper wire as shown in figure. The equivalent capacitance of the system is

Options

A. `(4pi epsilon_(0)ab)/(b -a)`
B. `4pi epsilon_(0)(a + b)`
C. `4 pi epsilon_(0)b`
D. `4pi epsilon_(0)a`

Answer

C

Explanation

The charge given to inner sphere will pass to the outer sphere. So, the capacitance of outer sphere will be `4pi epsilon_(0)b`. (As capacitance due to spherical conductor is `4pi epsilon_(0)r`, where `r` is radius of conductor)