Question

A solid metallic sphere of radius a carries total charge Q. No other charges are nearby. The electric field just outside its surface is keQ/a2 radially outward. At this close point, the uniformly charged surface of the sphere looks exactly like a uniform flat sheet of charge. What is the electric field strength inside the metallic sphere at r = a/2? Use σ = Q/4 π a2.

Answer 1

Please see below solution:

The electric field just outside its surface is = 2 , where is a radius of sphere, is a charge of sphere, = 1 4ε0 . The electric field is = 1 4ε0 2 = 1 ε0 ∙ = σ ε0 , where = 4 2 is an area of sphere, σ = Q S is a surface charge density. Answer: .