A point charge `q` si located at a distance `r` from the centre `O` of an uncharged conducting conducting spherical layer whose inside and outside radii are equal to `R_(1)` and `R_(2)` respectively. Find the potentail at the point `O` if `r lt R_(1)`.

Options

A. `((1)/(r )-(1)/(a)+(1)/(b))`
B. `((1)/(a)-(1)/(r )+(1)/(b))`
C. `((1)/(b)-(1)/(c )-(1)/(r))`
D. `((1)/(a)-(1)/(b )-(1)/(r))`

Answer

3