Question

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

• A. $\frac{4 \pi \varepsilon_{0} a b}{b-a}$
• B. $4 \pi \varepsilon_{0}(a+b)$
• C. $4 \pi \varepsilon_{0} b$
• D. $4 \pi \varepsilon_{0} a$

Answer 1

Answer: (C)

$4 \pi \varepsilon_{0} b$

Answer 2

The charge given to inner sphere will pass to the outer sphere So, the capacitance of outer sphere will be $4 \pi \varepsilon_{0} b$ (As capacitance due to spherical conductor is $4 \pi \varepsilon_{0} r$ where $r$ is radius of conductor)