What is thermal expansion? What are its types?

Asked by Topperlearning User | 13th Apr, 2015, 03:28: PM

Expert Answer:

All solids expand on heating. This phenomenon is called thermal expansion.
The types of thermal expansion are:
a.     Linear Expansion
In linear expansion there is an increase in length of the solid on heating.
 
begin mathsize 12px style straight L subscript straight T subscript 2 end subscript equals straight L subscript straight T subscript 1 end subscript open square brackets 1 plus straight alpha open parentheses straight T subscript 2 minus straight T subscript 1 close parentheses close square brackets end style
 
α is known as the coefficient of linear expansion.
 
b.    Aerial or Superficial Expansion
In superficial expansion there is an increase in the surface area of the solid on heating.
 
begin mathsize 12px style straight S subscript straight T subscript 2 end subscript equals straight S subscript straight T subscript 1 end subscript open square brackets 1 plus straight beta open parentheses straight T subscript 2 minus straight T subscript 1 close parentheses close square brackets end style
β is known as the coefficient of areal/superficial expansion.
 
c.    Cubical Expansion
There is increase in volume of solid on heating.

begin mathsize 12px style straight V subscript straight T subscript 2 end subscript equals straight V subscript straight T subscript 1 end subscript open square brackets 1 plus gamma open parentheses straight T subscript 2 minus straight T subscript 1 close parentheses close square brackets end style
γ is known as the coefficient of cubical expansion.
 

Answered by  | 13th Apr, 2015, 05:28: PM