Previous Year Question

A lactometer is an instrument used to measure the relative density of milk, and it works on Archimedes' Principle. NCERT also explicitly states that a lactometer works on Archimedes' Principle.

According to Archimedes' Principle, a body wholly or partially immersed in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced by it. How deeply a lactometer sinks in milk therefore depends on the density of the milk.