Assertion and Reason for Density and Optical Density – Rankers Physics

Refraction by Plane Surfaces: Practice Problem & Solution

Assertion (A): Turpentine is denser medium than water for light. Reason (R): Unit volume of turpentine is heavier than unit volume of water.  
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Refraction by Plane Surfaces. Understanding the underlying formula is key to arriving at the correct answer below:

Turpentine has a higher refractive index (optically denser) than water, so A is true. However, turpentine's mass density is less than water's, meaning a unit volume of turpentine is lighter than water. Therefore, R is false.

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