The electric force between two point charges separated by a certain distance in air is F . The distance at which they should be placed in a medium of relative permittivity k , so that the force remains the same, is

Step-by-step solution

Let d be the distance in air between two point charges and d_ m be the distance between them in medium. According to question, F=F_ m 1 4 ₀ q₁ q₂ d² = 1 4 ₀ k q₁ q₂ d_ m ² d²=k d_ m ² d_ m = d k