Question

Conducting sphere of radius `R_(1)` is covered by concentric sphere of radius `R_(2)`. Capacity of this combination is proportional to
A. `(R_(2)-R_(1))/(R_(1)R_(2))`
B. `(R_(2)+R_(1))/(R_(1)R_(2))`
C. `(R_(1)R_(2))/(R_(1)+R_(2))`
D. `(R_(1)R_(2))/(R_(2)-R_(1))`

Answer 1

Correct Answer - D
Capacity of spherical capacitor,
`C=4piepsilon_(0)((R_(1)R_(2))/(R_(2)-R_(1))) rArr C prop (R_(1)R_(2))/(R_(2)-R_(1))`