A spherical rubber balloon has a charge uniformly distributed over its surface. As the balloon is inflated, how does the electric field E vary INSIDE the balloon?

A) It decreases

B) It increases

C) It remains the same

D) Need more information

Solution: C. Inside a spherically symmetric charge distribution, the field will be zero. This is similar to the case of a charged conductor (of any shape). The excess charges will repel, so they will go to the surface until the field inside is zero.