Question

A charge Q is uniformly distributed in a dielectric sphere of radius R (having dielectric constant unity). This dielectric sphere is enclosed by a concentric spherical shell of radius 2R and having uniformly distributed charge 2Q. Which of the following graph correctly represents variation of electric field with distance r from the common centre?

A.
B.
C.
D.

Answer 1

Correct Answer - C
Use Gauses theorem.
Electric field inside uniformly distributed dielectric sphere
`E=r` (For `0ltrleR`)
Between the spheres
`Eprop(Q)/(r^(2))` (For `Rltrle2R`)
Outside the spheres
`E=(3Q)/(r^(2))` (For `2Rltr`)