Hi! I have a high school physics question. I know the concept of induction, and I also know what happens when a dielectric slab is placed between 2 plates of a capacitor. 2 charged particles are kept at a distance r. The mutual force of attraction/repulsion is F. What happens to the force when - 1) both particles are now kept in dielectric medium (K) 2) only one charge is kept in dielectric medium (k) other is in vacuum 3) when a dielectric slab (K) of thickness r/2 is kept between the 2 particles 4) when a random shaped dielectric solid body is placed between the 2 particles. Also, I found this question is test: 3 concentric spherical shells are placed in vacuum. The region between the inner 2 shells is filled with dielectric material (K). What is the potential on the surface of middle shell? The answer is independent of K. There is a possibility that it is incorrect. Can someone please explain? Thank you!