AP EAMCET Medical 24 Apr 2019 Shift 2 Paper

When two point charges are at some separation in air. the force between them is F1. If the space between them is filled with a dielectric of dielectric constant 4. then the force becomes F2. If half of the distance between them is filled with the same dielectric, then the force becomes F3. Then the ratio of F1,F2 and F3 is