A surface completely surrounds a +3.9 10-6 C charge. Find the electric flux through this surface when the surface is a sphere with a radius of 0.30 m, a sphere with a radius of 0.15 m, and a cube with edges that are 0.15 m long.
(a) a sphere with a radius of 0.30 m N ·
(b) a sphere with a radius of 0.15 m N ·
(c) a cube with edges that are 0.15 m long N ·