Question: Describe how the cubical expansivity of liquid can be determined by the use of balanced columns.
Ans: By the use of balanced columns, a simple method to determine the coefficient of real expansion of a liquid is Dulong and Petit’s experiment. It is based on the principle of hydrostatic. The apparatus uses a u-shaped glass tube ABCD filled with a liquid whose real expansivity should be determined. Initially, the liquid is at equal height as shown in the figure. One arm of the tube is surrounded by an ice-water jacket and another arm is surrounded with a steam jacket. The temperature of each jacket is noted by the thermometer fitted on them. To prevent the transformation of heat, a wet cloth is kept in the middle. At different heights, the pressure at the base is same.
Let, h1 and h2 be the height of the liquid column in limb AB and CD respectively,
Share on Social Media