Question
Physics Question on Ray optics and optical instruments
If optical density of a substance is more than that of water then the mass density of substance can be less than water. Optical density and mass density are not related.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
If both assertion and reason are true and reason is the correct explanation of assertion.
Solution
Optical density and mass density are not related to each other mass density is mass per unit volume. It is not possible that mass density of an optically denser medium may be less than that of an optically rarer medium (optical density is the ratio of the speed of light in two media), e.g., turpentine and water. Mass density of turpentine is less than that of water but its optical density is higher.