A spherical rubber balloon has a charge uniformly distributed over its surface. As the balloon is inflated, how does the electric field E vary outside the balloon, at some point well away from the surface?

A) It decreases

B) It increases

C) It remains the same

D) Need more information

Solution: C. Outside a spherically symmetric charge distribution, the charge may be treated as being entirely at the center of the sphere. Electric field of a point charge depends upon the charge and the distance. The charge does not change and the distance from the center doesn't change, so the electric field does not change.