`S_(1) and S_(2)` are two concentric spheres enclosing charges Q and 2Q respectively as shown in Fig.

(i) What is the ratio of electric flux through `S_(1) and S_(2)` ?
(ii) How will the electric flux through the sphere `S_(1)` charge, If a medium of dielectric constant K is introduced in the space inside `S_(1)` in place of air?
(iii) How wil the electric flux through sphere `S_(1)` change, if a medium of dielectric constant K is introduced in the space Inside `S_(2)` in place of air?

Explanation

(i) From Gauss's theoram
electric flux through `S_(1) is phi_(1) = (Q)/(in_(0))`
`:. (phi_(1))/(phi_(2)) = (1)/(3)`
(ii) When a medium of dielectric constant K is introduced in the space inside `S_(1)`, then
`phi_(1) = oint vec(E'), d vec(s) = oint ( vec(E))/(K), d vec(s) = (1)/(K) (Q)/(in_(0))`
(iii) On introducing dielectric medium inside `S_(2)`, electric flux through `S_(1)` will not change.