Answer to Question #27543 in Electricity and Magnetism for mena

Question

A point charge q is located at the center of a sphere of radius R. The sphere is then surrounded concentrically by a uniform ring having linear charge density λ and radius a (a >R). The flux through the sphere is
(q + λ*2πa)/ε0.
0.
(q - λ*2πa)/ε0.
q/εo.