A metal ball of radius `a` is located at a distance `l` from an indinite ideally conducting plane. The space around the ball is filled with a homongeous poorly conducting medium with resistivity `rho`. In the case of `a lt lt l` find :
(a) the current density at the conducting plane as a function of distance `r` from the ball if the potentail difference between the ball and the plane is equal to `V` ,
(b) the electric resistance of the medium between the balll and the plane.