Consider a uniform spherical charge distribution of radius `R_(1)` centred at the origin `O`. In this distribution a spherical cavity of radius `R_(2)`, centred at `P` with distance `OP = a = R_(1) - R_(2)` (fig) is made.If the electric field inside the cavity at position `vec(r )`, then the correct statement is
A. `vec( E)` is uniform,its magnitude is independent of `R_(2)` but its `r` direction depends on `vec( r)`.
B. `vec( E)` is uniform, its magnitude depends on `R_(2)` and its direction depends on `vec( r)`
C. `vec( E)` us uniform, its magnitude is independent of a but its direction depends on `vec(a)`.
D. `vec( E)` is uniform and both its magnitude and direction depend on `vec(a)`.