Physics > Thermometry and Thermal Expansion > 2.0 Thermal Expansions and it's types
Thermometry and Thermal Expansion
1.0 Introduction
2.0 Thermal Expansions and it's types
3.0 Relation between $\alpha ,\,\beta \,$ and $\gamma $
4.0 Variation of Density with Temperature
5.0 The Expansion of Water
6.0 Questions
2.1 Linear Expansion:
The change in one dimension (Length, width or height ) is known as Linear Expansion.
Experimentally, for small change in temperature, linear expansion is proportional to the change in temperature. If the temperature of a thin rod of length $L$ is increased by $\Delta T$$$\begin{equation} \begin{aligned} \frac{{L - {L_0}}}{{{L_0}}} = \frac{{\Delta L}}{{{L_0}}} \\ \frac{{\Delta L}}{{{L_0}}} = \alpha \Delta T\quad or\quad \Delta L = \alpha {L_0}\Delta T \\ L - {L_0} = \alpha {L_0}\Delta T \\ L = {L_0}\left( {1 + \alpha \Delta T} \right) \\\end{aligned} \end{equation} $$Where ${{L_0}}$ is the length of the original length of the rod and $L$ is the final length of the rod, $\alpha $ is the coefficient of linear expansion of the material. Its units are ${K^{ - 1}}\;or\;{\left( {^oC} \right)^{ - 1}}$
