Two spherical cavities of radii `a` and `b` are hollowed out from the interior of a neutral conducting sphere of radius `R`. At the center of each cavity , a point charge is placed . Call these charges `q_(a)` and `q_(b)`.
The electric field inside the cavity of radius `a` at a distance `r` from the center of cavity is
A. `(1)/( 4 pi epsilon_(0)) (q_(a))/(r^(2))`
B. `(1)/( 4 pi epsilon_(0)) (q_(a))/(r^(2))`
C. `(1)/( 4 pi epsilon_(0)) ( q_(a) + q_(b))/( r^(2))`
D. zero