Physics Class 11 Chapter 12. Thermodynamics | Page 10

2 . Expansion of Liquids In liquids only expansion in volume takes place on heating .
( i ) Apparent Expansion of Liquids When expansion of th container containing liquid , on heating is not taken into accoun then observed expansion is called apparent expansion of liquids .
Coefficient of apparent expansion of a liquid
( ii ) Real Expansion of Liquids When expansion of the container , containing liquid , on heating is also taken into account , then observed expansion is called real expansion of liquids .
Coefficient of real expansion of a liquid
Both , yr , and ya are measured in ° C -1 . We can show that yr = ya + yg
where , yr , and ya are coefficient of real and apparent expansion of liquids and yg is coefficient of cubical expansion of the container .
Anamalous Expansion of Water
When temperature of water is increased from 0 ° C , then its vol decreases upto 4 ° C , becomes minimum at 4 ° C and then increases . behaviour of water around 4 ° C is called , anamalous expansion water .
3 . Expansion of Gases There are two types of coefficient of expansion in gases
( i ) Volume Coefficient (& gamma ; v ) At constant pressure , the change in volume per unit volume per degree celsius is called volume coefficient .
where V0 , V1 , and V2 are volumes of the gas at 0 ° C , t1 ° C and t2 ° C .