Question

Find the correlation.

₂n₁ : Refractive index of medium 1 with respect to medium 2 : : ₁n₂ : ______

Answer 1

₂n₁ : Refractive index of medium 1 with respect to medium 2 : : ₁n₂ : Refractive index of medium 2 with respect to medium 1

Explanation: 

The first part of the analogy establishes the naming convention: the subscript on the right (1) is the medium whose refractive index is being measured, and the subscript on the left (2) is the reference medium. Applying this exact same pattern to the second term, ₁n₂ reverses the roles, representing the refractive index of medium 2 with respect to medium 1.