Two concentric thin metallic spherical shells of radii `R_(1)` and `R_(2)` (where `R_(1) lt R_(2)`) are charged with `q_(1) and q_(2)` coulombs, respectively. Using Gauss' theorem show that,
(i) the electric field intensity for radius `r lt R_(1)` is zero,
(ii) the electic field intensity for radius r, where `R_(1) lt r lt R_(2),` is `(1)/(4pi epsilon_(0)).(q_(1))/(r^(2))` and
(iii) the electri field intensity for radius `r gt R_(2)` is `(1)/(4pi epsilon_(0)).(q_(1)+q_(2))/(r^(2))`.