Question

The lactometer is a device used for measuring the density of :

• A. Lighter liquids
• B. Heavier liquids
• C. Milk
• D. None of these

Answer 1

The correct option is C

Milk

Explanation

1. The relative density of pure milk is “1.045” and if the milk is adultered, a simple hydrometer cannot detect it because a simple hydrometer can't record a small change in the density of milk.
2. A special hydrometer called “lactometer” is designed in such a way that it can measure densities within the range of "1 g/cm³ to 1.045 g/cm³.
3. A lactometer is made highly sensitive by reducing the area of the cross-section of its stem and increasing its length.

Hence, option (c) is correct.