Question

(a) Describe the action of a hydrometer.

(b) A piece of metal 100 cm long at 100°C is found to be 99.4 cm long when placed in severe conditions of low temperatures. Calculate the final temperature.

Answer 1

A hydrometer is an instrument used for measuring the specific density of liquids based on the concept of buoyancy. It consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast for stability, and a narrow stem with graduations for measuring. The point at which the liquid surface touches the stem indicates the relative density of the liquid.

Step-by-step explanation:

A hydrometer is an instrument used for measuring the specific density of liquids based on the concept of buoyancy. It consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast such as lead or mercury for stability, and a narrow stem with graduations for measuring. When the hydrometer is gently lowered into a liquid, it floats freely and the point at which the liquid surface touches the stem indicates the relative density of the liquid.