Question

Electric Field Intensity at various points due to a uniformly charged spherical shell (thin & thick both).​

Answer 1

The field around a charged spherical shell is therefore the same as the field around a point charge. Inside the Gaussian surface there is the whole charged shell, thus the charge can be evaluated through the shell volume V and the charge density ρ.

Answer 2

Sphere of constant surface density causes exactly the same electric field (outside the sphere) as a point charge in the center with the use Gauss law and symmetry.

Gauss law predicts that constant surface density sphere does not cause any field inside it.

With calculating the E(r) you can imagine all charge inside the ball with radious r lies in the center. q enclosed would be q = 4*pi*k*(b^3-a^3)/3 which would lead to an electric field of k(b^3-a^3)/3*epsilon-naught*r^2 in the r hat direction.