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Electric Charges And Fields

Question
CBSEENPH12037272

Show that for a uniformly charged hollow sphere, the electric field has a maximum value at the surface of the sphere.

Solution

Consider a thin spherical shell of radius 'R' with centre O. Let, a charge +q be distributed uniformly on the surface of the shell. 
According to gaussian theorem, 

           E.ds = E. n.ds = qεo 
Surface area of the sphere = 4πr2 

 E. 4πr2 = qεo

Now, at a point on the surface area of the shell 
Let, σ be the surface charge density on the shell, 
then, 
             q = 4πR2σ 

  E = 4πR2 σ4πεoR2 = σε 

Therefore, 
                   E = σεo 
which is the required electric field at the surface of the shell.