Solution:
The following are the elements that influence a medium’s refractive index:
(i) Medium nature (e.g. μg = 1.5, μw = 1.33): The lower the speed of light in the medium compared to air, the higher the refractive index of the medium.
(ii) Physical conditions, such as temperature: As the temperature rises, the speed of light in the medium rises, lowering the refractive index of the medium.