Question

What is linear thermal expansion?

Answer 1

To address the question, we must first grasp certain fundamentals of thermal expansion. When a substance's temperature rises, the volume of the material also rises. In general, this is referred to as thermal expansion. A fractional change in volume or length per unit change in temperature is what thermal expansion is defined as. In the case of a solid expansion, the linear expansion coefficient is commonly used.

Complete step by step answer:
Linear Expansion: The term "expansion" refers to a change or increase in length. Linear expansion is defined as a change in length in one dimension (length) over a volume. A change in temperature causes the expansion in this situation. As a result, a change in temperature is likely to result in a change in expansion rate. When a substance is exposed to heat radiation, this description explains how long it can maintain its original shape and size. Linear expansion refers to the length change generated by heat. The formula for linear expansion is as follows:
$\dfrac{{\Delta L}}{L} = {\alpha _L}\Delta T$
Where,
The temperature change is denoted by $\Delta T$
The change in length is denoted by the letter $\Delta L$
The linear coefficient of thermal expansion is denoted by ${\alpha _L}$
The origin length is $L$

Note: It's worth mentioning that the volumetric expansion is three times that of the linear expansion, while the surface expansion is two times that of the linear expansion. Metals are used for this expansion because they have the ability to expand when heated. Metal expands in every direction.