Assertion (A): The refractive index of glass is greater than that of air. Reason (R): Optical density is directly proportional to mass density, which causes a proportional refractive index. Choose the correct answer.
Options

Question

Assertion (A): The refractive index of glass is greater than that of air. Reason (R): Optical density is directly proportional to mass density, which causes a proportional refractive index. Choose the correct answer.

Options

G1 Physics · Accepted Answer

Glass generally has a refractive index greater than air, so Assertion A is true. However, optical density is not simply proportional to mass density. Refractive index depends on the electromagnetic response of the medium, not merely on its ordinary mass density. Therefore Reason R is false. Correct option: C.