A conducting sphere `A` of radius `a` ,with charge `Q` , is placed concentrically inside a conducting shell `B` of radius `b` . `B` is earthed. `C` is the common centre of the `A` and `B`
A. The field at a distance `r` form `C` where `alerleb` is `k(Q)/(r^(2))`
B. the potential at a distance `r` form `C`, where `alerleb` is `k(Q)/(r^(2))`
C. the potential difference between `A` and `B` is
D. The potential at a distance `r` from `C` where `alerleb` is
